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llvm-project/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp

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//===-- ARMBaseInstrInfo.cpp - ARM Instruction Information ----------------===//
//
// 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 Base ARM implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "ARMBaseRegisterInfo.h"
#include "ARMConstantPoolValue.h"
#include "ARMFeatures.h"
#include "ARMHazardRecognizer.h"
#include "ARMMachineFunctionInfo.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetSchedule.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "arm-instrinfo"
#define GET_INSTRINFO_CTOR_DTOR
#include "ARMGenInstrInfo.inc"
static cl::opt<bool>
EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
cl::desc("Enable ARM 2-addr to 3-addr conv"));
static cl::opt<bool>
WidenVMOVS("widen-vmovs", cl::Hidden, cl::init(true),
cl::desc("Widen ARM vmovs to vmovd when possible"));
static cl::opt<unsigned>
SwiftPartialUpdateClearance("swift-partial-update-clearance",
cl::Hidden, cl::init(12),
cl::desc("Clearance before partial register updates"));
/// ARM_MLxEntry - Record information about MLA / MLS instructions.
struct ARM_MLxEntry {
uint16_t MLxOpc; // MLA / MLS opcode
uint16_t MulOpc; // Expanded multiplication opcode
uint16_t AddSubOpc; // Expanded add / sub opcode
bool NegAcc; // True if the acc is negated before the add / sub.
bool HasLane; // True if instruction has an extra "lane" operand.
};
static const ARM_MLxEntry ARM_MLxTable[] = {
// MLxOpc, MulOpc, AddSubOpc, NegAcc, HasLane
// fp scalar ops
{ ARM::VMLAS, ARM::VMULS, ARM::VADDS, false, false },
{ ARM::VMLSS, ARM::VMULS, ARM::VSUBS, false, false },
{ ARM::VMLAD, ARM::VMULD, ARM::VADDD, false, false },
{ ARM::VMLSD, ARM::VMULD, ARM::VSUBD, false, false },
{ ARM::VNMLAS, ARM::VNMULS, ARM::VSUBS, true, false },
{ ARM::VNMLSS, ARM::VMULS, ARM::VSUBS, true, false },
{ ARM::VNMLAD, ARM::VNMULD, ARM::VSUBD, true, false },
{ ARM::VNMLSD, ARM::VMULD, ARM::VSUBD, true, false },
// fp SIMD ops
{ ARM::VMLAfd, ARM::VMULfd, ARM::VADDfd, false, false },
{ ARM::VMLSfd, ARM::VMULfd, ARM::VSUBfd, false, false },
{ ARM::VMLAfq, ARM::VMULfq, ARM::VADDfq, false, false },
{ ARM::VMLSfq, ARM::VMULfq, ARM::VSUBfq, false, false },
{ ARM::VMLAslfd, ARM::VMULslfd, ARM::VADDfd, false, true },
{ ARM::VMLSslfd, ARM::VMULslfd, ARM::VSUBfd, false, true },
{ ARM::VMLAslfq, ARM::VMULslfq, ARM::VADDfq, false, true },
{ ARM::VMLSslfq, ARM::VMULslfq, ARM::VSUBfq, false, true },
};
ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget& STI)
: ARMGenInstrInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
Subtarget(STI) {
for (unsigned i = 0, e = array_lengthof(ARM_MLxTable); i != e; ++i) {
if (!MLxEntryMap.insert(std::make_pair(ARM_MLxTable[i].MLxOpc, i)).second)
llvm_unreachable("Duplicated entries?");
MLxHazardOpcodes.insert(ARM_MLxTable[i].AddSubOpc);
MLxHazardOpcodes.insert(ARM_MLxTable[i].MulOpc);
}
}
// Use a ScoreboardHazardRecognizer for prepass ARM scheduling. TargetInstrImpl
// currently defaults to no prepass hazard recognizer.
ScheduleHazardRecognizer *
ARMBaseInstrInfo::CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
const ScheduleDAG *DAG) const {
if (usePreRAHazardRecognizer()) {
const InstrItineraryData *II =
static_cast<const ARMSubtarget *>(STI)->getInstrItineraryData();
return new ScoreboardHazardRecognizer(II, DAG, "pre-RA-sched");
}
return TargetInstrInfo::CreateTargetHazardRecognizer(STI, DAG);
}
ScheduleHazardRecognizer *ARMBaseInstrInfo::
CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
const ScheduleDAG *DAG) const {
if (Subtarget.isThumb2() || Subtarget.hasVFP2())
return (ScheduleHazardRecognizer *)new ARMHazardRecognizer(II, DAG);
return TargetInstrInfo::CreateTargetPostRAHazardRecognizer(II, DAG);
}
MachineInstr *
ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables *LV) const {
// FIXME: Thumb2 support.
if (!EnableARM3Addr)
return nullptr;
MachineInstr *MI = MBBI;
MachineFunction &MF = *MI->getParent()->getParent();
uint64_t TSFlags = MI->getDesc().TSFlags;
bool isPre = false;
switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
default: return nullptr;
case ARMII::IndexModePre:
isPre = true;
break;
case ARMII::IndexModePost:
break;
}
// Try splitting an indexed load/store to an un-indexed one plus an add/sub
// operation.
unsigned MemOpc = getUnindexedOpcode(MI->getOpcode());
if (MemOpc == 0)
return nullptr;
MachineInstr *UpdateMI = nullptr;
MachineInstr *MemMI = nullptr;
unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
const MCInstrDesc &MCID = MI->getDesc();
unsigned NumOps = MCID.getNumOperands();
bool isLoad = !MI->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: llvm_unreachable("Unknown indexed op!");
case ARMII::AddrMode2: {
bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
unsigned Amt = ARM_AM::getAM2Offset(OffImm);
if (OffReg == 0) {
if (ARM_AM::getSOImmVal(Amt) == -1)
// Can't encode it in a so_imm operand. This transformation will
// add more than 1 instruction. Abandon!
return nullptr;
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(Amt)
.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(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBrsi : ARM::ADDrsi), WBReg)
.addReg(BaseReg).addReg(OffReg).addReg(0).addImm(SOOpc)
.addImm(Pred).addReg(0).addReg(0);
} else
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
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(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(Amt)
.addImm(Pred).addReg(0).addReg(0);
else
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
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(MF, MI->getDebugLoc(),
get(MemOpc), MI->getOperand(0).getReg())
.addReg(WBReg).addImm(0).addImm(Pred);
else
MemMI = BuildMI(MF, MI->getDebugLoc(),
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(MF, MI->getDebugLoc(),
get(MemOpc), MI->getOperand(0).getReg())
.addReg(BaseReg).addImm(0).addImm(Pred);
else
MemMI = BuildMI(MF, MI->getDebugLoc(),
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.
if (LV) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && 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];
if (!NewMI->readsRegister(Reg))
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
ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
TBB = nullptr;
FBB = nullptr;
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin())
return false; // Empty blocks are easy.
--I;
// Walk backwards from the end of the basic block until the branch is
// analyzed or we give up.
while (isPredicated(*I) || I->isTerminator() || I->isDebugValue()) {
// Flag to be raised on unanalyzeable instructions. This is useful in cases
// where we want to clean up on the end of the basic block before we bail
// out.
bool CantAnalyze = false;
// Skip over DEBUG values and predicated nonterminators.
while (I->isDebugValue() || !I->isTerminator()) {
if (I == MBB.begin())
return false;
--I;
}
if (isIndirectBranchOpcode(I->getOpcode()) ||
isJumpTableBranchOpcode(I->getOpcode())) {
// Indirect branches and jump tables can't be analyzed, but we still want
// to clean up any instructions at the tail of the basic block.
CantAnalyze = true;
} else if (isUncondBranchOpcode(I->getOpcode())) {
TBB = I->getOperand(0).getMBB();
} else if (isCondBranchOpcode(I->getOpcode())) {
// Bail out if we encounter multiple conditional branches.
if (!Cond.empty())
return true;
assert(!FBB && "FBB should have been null.");
FBB = TBB;
TBB = I->getOperand(0).getMBB();
Cond.push_back(I->getOperand(1));
Cond.push_back(I->getOperand(2));
} else if (I->isReturn()) {
// Returns can't be analyzed, but we should run cleanup.
CantAnalyze = !isPredicated(*I);
} else {
// We encountered other unrecognized terminator. Bail out immediately.
return true;
}
// Cleanup code - to be run for unpredicated unconditional branches and
// returns.
if (!isPredicated(*I) &&
(isUncondBranchOpcode(I->getOpcode()) ||
isIndirectBranchOpcode(I->getOpcode()) ||
isJumpTableBranchOpcode(I->getOpcode()) ||
I->isReturn())) {
// Forget any previous condition branch information - it no longer applies.
Cond.clear();
FBB = nullptr;
// If we can modify the function, delete everything below this
// unconditional branch.
if (AllowModify) {
MachineBasicBlock::iterator DI = std::next(I);
while (DI != MBB.end()) {
MachineInstr *InstToDelete = DI;
++DI;
InstToDelete->eraseFromParent();
}
}
}
if (CantAnalyze)
return true;
if (I == MBB.begin())
return false;
--I;
}
// We made it past the terminators without bailing out - we must have
// analyzed this branch successfully.
return false;
}
unsigned ARMBaseInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return 0;
if (!isUncondBranchOpcode(I->getOpcode()) &&
!isCondBranchOpcode(I->getOpcode()))
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (!isCondBranchOpcode(I->getOpcode()))
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned ARMBaseInstrInfo::InsertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
const DebugLoc &DL) const {
ARMFunctionInfo *AFI = MBB.getParent()->getInfo<ARMFunctionInfo>();
int BOpc = !AFI->isThumbFunction()
? ARM::B : (AFI->isThumb2Function() ? ARM::t2B : ARM::tB);
int BccOpc = !AFI->isThumbFunction()
? ARM::Bcc : (AFI->isThumb2Function() ? ARM::t2Bcc : ARM::tBcc);
bool isThumb = AFI->isThumbFunction() || AFI->isThumb2Function();
// 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!");
// For conditional branches, we use addOperand to preserve CPSR flags.
if (!FBB) {
if (Cond.empty()) { // Unconditional branch?
if (isThumb)
BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB).addImm(ARMCC::AL).addReg(0);
else
BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB);
} else
BuildMI(&MBB, DL, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addOperand(Cond[1]);
return 1;
}
// Two-way conditional branch.
BuildMI(&MBB, DL, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addOperand(Cond[1]);
if (isThumb)
BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB).addImm(ARMCC::AL).addReg(0);
else
BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB);
return 2;
}
bool ARMBaseInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
Cond[0].setImm(ARMCC::getOppositeCondition(CC));
return false;
}
bool ARMBaseInstrInfo::isPredicated(const MachineInstr &MI) const {
if (MI.isBundle()) {
MachineBasicBlock::const_instr_iterator I = MI.getIterator();
MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
while (++I != E && I->isInsideBundle()) {
int PIdx = I->findFirstPredOperandIdx();
if (PIdx != -1 && I->getOperand(PIdx).getImm() != ARMCC::AL)
return true;
}
return false;
}
int PIdx = MI.findFirstPredOperandIdx();
return PIdx != -1 && MI.getOperand(PIdx).getImm() != ARMCC::AL;
}
bool ARMBaseInstrInfo::PredicateInstruction(
MachineInstr &MI, ArrayRef<MachineOperand> Pred) const {
unsigned Opc = MI.getOpcode();
if (isUncondBranchOpcode(Opc)) {
MI.setDesc(get(getMatchingCondBranchOpcode(Opc)));
MachineInstrBuilder(*MI.getParent()->getParent(), MI)
.addImm(Pred[0].getImm())
.addReg(Pred[1].getReg());
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 ARMBaseInstrInfo::SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
ArrayRef<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 ARMBaseInstrInfo::DefinesPredicate(
MachineInstr &MI, std::vector<MachineOperand> &Pred) const {
bool Found = false;
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI.getOperand(i);
if ((MO.isRegMask() && MO.clobbersPhysReg(ARM::CPSR)) ||
(MO.isReg() && MO.isDef() && MO.getReg() == ARM::CPSR)) {
Pred.push_back(MO);
Found = true;
}
}
return Found;
}
static bool isCPSRDefined(const MachineInstr *MI) {
for (const auto &MO : MI->operands())
if (MO.isReg() && MO.getReg() == ARM::CPSR && MO.isDef() && !MO.isDead())
return true;
return false;
}
static bool isEligibleForITBlock(const MachineInstr *MI) {
switch (MI->getOpcode()) {
default: return true;
case ARM::tADC: // ADC (register) T1
case ARM::tADDi3: // ADD (immediate) T1
case ARM::tADDi8: // ADD (immediate) T2
case ARM::tADDrr: // ADD (register) T1
case ARM::tAND: // AND (register) T1
case ARM::tASRri: // ASR (immediate) T1
case ARM::tASRrr: // ASR (register) T1
case ARM::tBIC: // BIC (register) T1
case ARM::tEOR: // EOR (register) T1
case ARM::tLSLri: // LSL (immediate) T1
case ARM::tLSLrr: // LSL (register) T1
case ARM::tLSRri: // LSR (immediate) T1
case ARM::tLSRrr: // LSR (register) T1
case ARM::tMUL: // MUL T1
case ARM::tMVN: // MVN (register) T1
case ARM::tORR: // ORR (register) T1
case ARM::tROR: // ROR (register) T1
case ARM::tRSB: // RSB (immediate) T1
case ARM::tSBC: // SBC (register) T1
case ARM::tSUBi3: // SUB (immediate) T1
case ARM::tSUBi8: // SUB (immediate) T2
case ARM::tSUBrr: // SUB (register) T1
return !isCPSRDefined(MI);
}
}
/// isPredicable - Return true if the specified instruction can be predicated.
/// By default, this returns true for every instruction with a
/// PredicateOperand.
bool ARMBaseInstrInfo::isPredicable(MachineInstr &MI) const {
if (!MI.isPredicable())
return false;
if (!isEligibleForITBlock(&MI))
return false;
ARMFunctionInfo *AFI =
MI.getParent()->getParent()->getInfo<ARMFunctionInfo>();
if (AFI->isThumb2Function()) {
if (getSubtarget().restrictIT())
return isV8EligibleForIT(&MI);
} else { // non-Thumb
if ((MI.getDesc().TSFlags & ARMII::DomainMask) == ARMII::DomainNEON)
return false;
}
return true;
}
namespace llvm {
template <> bool IsCPSRDead<MachineInstr>(MachineInstr *MI) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || MO.isUndef() || MO.isUse())
continue;
if (MO.getReg() != ARM::CPSR)
continue;
if (!MO.isDead())
return false;
}
// all definitions of CPSR are dead
return true;
}
}
/// GetInstSize - Return the size of the specified MachineInstr.
///
unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
const MachineBasicBlock &MBB = *MI->getParent();
const MachineFunction *MF = MBB.getParent();
const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();
const MCInstrDesc &MCID = MI->getDesc();
if (MCID.getSize())
return MCID.getSize();
// If this machine instr is an inline asm, measure it.
if (MI->getOpcode() == ARM::INLINEASM)
return getInlineAsmLength(MI->getOperand(0).getSymbolName(), *MAI);
unsigned Opc = MI->getOpcode();
switch (Opc) {
default:
// pseudo-instruction sizes are zero.
return 0;
case TargetOpcode::BUNDLE:
return getInstBundleLength(MI);
case ARM::MOVi16_ga_pcrel:
case ARM::MOVTi16_ga_pcrel:
case ARM::t2MOVi16_ga_pcrel:
case ARM::t2MOVTi16_ga_pcrel:
return 4;
case ARM::MOVi32imm:
case ARM::t2MOVi32imm:
return 8;
case ARM::CONSTPOOL_ENTRY:
case ARM::JUMPTABLE_INSTS:
case ARM::JUMPTABLE_ADDRS:
case ARM::JUMPTABLE_TBB:
case ARM::JUMPTABLE_TBH:
// If this machine instr is a constant pool entry, its size is recorded as
// operand #2.
return MI->getOperand(2).getImm();
case ARM::Int_eh_sjlj_longjmp:
return 16;
case ARM::tInt_eh_sjlj_longjmp:
case ARM::tInt_WIN_eh_sjlj_longjmp:
return 10;
case ARM::Int_eh_sjlj_setjmp:
case ARM::Int_eh_sjlj_setjmp_nofp:
return 20;
case ARM::tInt_eh_sjlj_setjmp:
case ARM::t2Int_eh_sjlj_setjmp:
case ARM::t2Int_eh_sjlj_setjmp_nofp:
return 12;
case ARM::SPACE:
return MI->getOperand(1).getImm();
}
}
unsigned ARMBaseInstrInfo::getInstBundleLength(const MachineInstr *MI) const {
unsigned Size = 0;
MachineBasicBlock::const_instr_iterator I = MI->getIterator();
MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
while (++I != E && I->isInsideBundle()) {
assert(!I->isBundle() && "No nested bundle!");
Size += GetInstSizeInBytes(&*I);
}
return Size;
}
void ARMBaseInstrInfo::copyFromCPSR(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, bool KillSrc,
const ARMSubtarget &Subtarget) const {
unsigned Opc = Subtarget.isThumb()
? (Subtarget.isMClass() ? ARM::t2MRS_M : ARM::t2MRS_AR)
: ARM::MRS;
MachineInstrBuilder MIB =
BuildMI(MBB, I, I->getDebugLoc(), get(Opc), DestReg);
// There is only 1 A/R class MRS instruction, and it always refers to
// APSR. However, there are lots of other possibilities on M-class cores.
if (Subtarget.isMClass())
MIB.addImm(0x800);
AddDefaultPred(MIB);
MIB.addReg(ARM::CPSR, RegState::Implicit | getKillRegState(KillSrc));
}
void ARMBaseInstrInfo::copyToCPSR(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned SrcReg, bool KillSrc,
const ARMSubtarget &Subtarget) const {
unsigned Opc = Subtarget.isThumb()
? (Subtarget.isMClass() ? ARM::t2MSR_M : ARM::t2MSR_AR)
: ARM::MSR;
MachineInstrBuilder MIB = BuildMI(MBB, I, I->getDebugLoc(), get(Opc));
if (Subtarget.isMClass())
MIB.addImm(0x800);
else
MIB.addImm(8);
MIB.addReg(SrcReg, getKillRegState(KillSrc));
AddDefaultPred(MIB);
MIB.addReg(ARM::CPSR, RegState::Implicit | RegState::Define);
}
void ARMBaseInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, unsigned DestReg,
unsigned SrcReg, bool KillSrc) const {
bool GPRDest = ARM::GPRRegClass.contains(DestReg);
bool GPRSrc = ARM::GPRRegClass.contains(SrcReg);
if (GPRDest && GPRSrc) {
AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::MOVr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))));
return;
}
bool SPRDest = ARM::SPRRegClass.contains(DestReg);
bool SPRSrc = ARM::SPRRegClass.contains(SrcReg);
unsigned Opc = 0;
if (SPRDest && SPRSrc)
Opc = ARM::VMOVS;
else if (GPRDest && SPRSrc)
Opc = ARM::VMOVRS;
else if (SPRDest && GPRSrc)
Opc = ARM::VMOVSR;
else if (ARM::DPRRegClass.contains(DestReg, SrcReg) && !Subtarget.isFPOnlySP())
Opc = ARM::VMOVD;
else if (ARM::QPRRegClass.contains(DestReg, SrcReg))
Opc = ARM::VORRq;
if (Opc) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc), DestReg);
MIB.addReg(SrcReg, getKillRegState(KillSrc));
if (Opc == ARM::VORRq)
MIB.addReg(SrcReg, getKillRegState(KillSrc));
AddDefaultPred(MIB);
return;
}
// Handle register classes that require multiple instructions.
unsigned BeginIdx = 0;
unsigned SubRegs = 0;
int Spacing = 1;
// Use VORRq when possible.
if (ARM::QQPRRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VORRq;
BeginIdx = ARM::qsub_0;
SubRegs = 2;
} else if (ARM::QQQQPRRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VORRq;
BeginIdx = ARM::qsub_0;
SubRegs = 4;
// Fall back to VMOVD.
} else if (ARM::DPairRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 2;
} else if (ARM::DTripleRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 3;
} else if (ARM::DQuadRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 4;
} else if (ARM::GPRPairRegClass.contains(DestReg, SrcReg)) {
Opc = Subtarget.isThumb2() ? ARM::tMOVr : ARM::MOVr;
BeginIdx = ARM::gsub_0;
SubRegs = 2;
} else if (ARM::DPairSpcRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 2;
Spacing = 2;
} else if (ARM::DTripleSpcRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 3;
Spacing = 2;
} else if (ARM::DQuadSpcRegClass.contains(DestReg, SrcReg)) {
Opc = ARM::VMOVD;
BeginIdx = ARM::dsub_0;
SubRegs = 4;
Spacing = 2;
} else if (ARM::DPRRegClass.contains(DestReg, SrcReg) && Subtarget.isFPOnlySP()) {
Opc = ARM::VMOVS;
BeginIdx = ARM::ssub_0;
SubRegs = 2;
} else if (SrcReg == ARM::CPSR) {
copyFromCPSR(MBB, I, DestReg, KillSrc, Subtarget);
return;
} else if (DestReg == ARM::CPSR) {
copyToCPSR(MBB, I, SrcReg, KillSrc, Subtarget);
return;
}
assert(Opc && "Impossible reg-to-reg copy");
const TargetRegisterInfo *TRI = &getRegisterInfo();
MachineInstrBuilder Mov;
// Copy register tuples backward when the first Dest reg overlaps with SrcReg.
if (TRI->regsOverlap(SrcReg, TRI->getSubReg(DestReg, BeginIdx))) {
BeginIdx = BeginIdx + ((SubRegs - 1) * Spacing);
Spacing = -Spacing;
}
#ifndef NDEBUG
SmallSet<unsigned, 4> DstRegs;
#endif
for (unsigned i = 0; i != SubRegs; ++i) {
unsigned Dst = TRI->getSubReg(DestReg, BeginIdx + i * Spacing);
unsigned Src = TRI->getSubReg(SrcReg, BeginIdx + i * Spacing);
assert(Dst && Src && "Bad sub-register");
#ifndef NDEBUG
assert(!DstRegs.count(Src) && "destructive vector copy");
DstRegs.insert(Dst);
#endif
Mov = BuildMI(MBB, I, I->getDebugLoc(), get(Opc), Dst).addReg(Src);
// VORR takes two source operands.
if (Opc == ARM::VORRq)
Mov.addReg(Src);
Mov = AddDefaultPred(Mov);
// MOVr can set CC.
if (Opc == ARM::MOVr)
Mov = AddDefaultCC(Mov);
}
// Add implicit super-register defs and kills to the last instruction.
Mov->addRegisterDefined(DestReg, TRI);
if (KillSrc)
Mov->addRegisterKilled(SrcReg, TRI);
}
const MachineInstrBuilder &
ARMBaseInstrInfo::AddDReg(MachineInstrBuilder &MIB, unsigned Reg,
unsigned SubIdx, unsigned State,
const TargetRegisterInfo *TRI) const {
if (!SubIdx)
return MIB.addReg(Reg, State);
if (TargetRegisterInfo::isPhysicalRegister(Reg))
return MIB.addReg(TRI->getSubReg(Reg, SubIdx), State);
return MIB.addReg(Reg, State, SubIdx);
}
void ARMBaseInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
MFI.getObjectSize(FI), Align);
switch (RC->getSize()) {
case 4:
if (ARM::GPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::STRi12))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRS))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else
llvm_unreachable("Unknown reg class!");
break;
case 8:
if (ARM::DPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRD))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
if (Subtarget.hasV5TEOps()) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::STRD));
AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI);
AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI);
MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO);
AddDefaultPred(MIB);
} else {
// Fallback to STM instruction, which has existed since the dawn of
// time.
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::STMIA))
.addFrameIndex(FI).addMemOperand(MMO));
AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI);
AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 16:
if (ARM::DPairRegClass.hasSubClassEq(RC)) {
// Use aligned spills if the stack can be realigned.
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1q64))
.addFrameIndex(FI).addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO));
} else {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMQIA))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addMemOperand(MMO));
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 24:
if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
// Use aligned spills if the stack can be realigned.
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1d64TPseudo))
.addFrameIndex(FI).addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
.addFrameIndex(FI))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 32:
if (ARM::QQPRRegClass.hasSubClassEq(RC) || ARM::DQuadRegClass.hasSubClassEq(RC)) {
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
// FIXME: It's possible to only store part of the QQ register if the
// spilled def has a sub-register index.
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1d64QPseudo))
.addFrameIndex(FI).addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
.addFrameIndex(FI))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 64:
if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
.addFrameIndex(FI))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_4, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_5, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_6, 0, TRI);
AddDReg(MIB, SrcReg, ARM::dsub_7, 0, TRI);
} else
llvm_unreachable("Unknown reg class!");
break;
default:
llvm_unreachable("Unknown reg class!");
}
}
unsigned
ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case ARM::STRrs:
case ARM::t2STRs: // FIXME: don't use t2STRs to access frame.
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isReg() &&
MI->getOperand(3).isImm() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::STRi12:
case ARM::t2STRi12:
case ARM::tSTRspi:
case ARM::VSTRD:
case ARM::VSTRS:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::VST1q64:
case ARM::VST1d64TPseudo:
case ARM::VST1d64QPseudo:
if (MI->getOperand(0).isFI() &&
MI->getOperand(2).getSubReg() == 0) {
FrameIndex = MI->getOperand(0).getIndex();
return MI->getOperand(2).getReg();
}
break;
case ARM::VSTMQIA:
if (MI->getOperand(1).isFI() &&
MI->getOperand(0).getSubReg() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned ARMBaseInstrInfo::isStoreToStackSlotPostFE(const MachineInstr *MI,
int &FrameIndex) const {
const MachineMemOperand *Dummy;
return MI->mayStore() && hasStoreToStackSlot(MI, Dummy, FrameIndex);
}
void ARMBaseInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
MFI.getObjectSize(FI), Align);
switch (RC->getSize()) {
case 4:
if (ARM::GPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::LDRi12), DestReg)
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRS), DestReg)
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else
llvm_unreachable("Unknown reg class!");
break;
case 8:
if (ARM::DPRRegClass.hasSubClassEq(RC)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRD), DestReg)
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
} else if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
MachineInstrBuilder MIB;
if (Subtarget.hasV5TEOps()) {
MIB = BuildMI(MBB, I, DL, get(ARM::LDRD));
AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI);
AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI);
MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO);
AddDefaultPred(MIB);
} else {
// Fallback to LDM instruction, which has existed since the dawn of
// time.
MIB = AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::LDMIA))
.addFrameIndex(FI).addMemOperand(MMO));
MIB = AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI);
}
if (TargetRegisterInfo::isPhysicalRegister(DestReg))
MIB.addReg(DestReg, RegState::ImplicitDefine);
} else
llvm_unreachable("Unknown reg class!");
break;
case 16:
if (ARM::DPairRegClass.hasSubClassEq(RC)) {
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1q64), DestReg)
.addFrameIndex(FI).addImm(16)
.addMemOperand(MMO));
} else {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMQIA), DestReg)
.addFrameIndex(FI)
.addMemOperand(MMO));
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 24:
if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1d64TPseudo), DestReg)
.addFrameIndex(FI).addImm(16)
.addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI)
.addMemOperand(MMO));
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
if (TargetRegisterInfo::isPhysicalRegister(DestReg))
MIB.addReg(DestReg, RegState::ImplicitDefine);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 32:
if (ARM::QQPRRegClass.hasSubClassEq(RC) || ARM::DQuadRegClass.hasSubClassEq(RC)) {
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1d64QPseudo), DestReg)
.addFrameIndex(FI).addImm(16)
.addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead, TRI);
if (TargetRegisterInfo::isPhysicalRegister(DestReg))
MIB.addReg(DestReg, RegState::ImplicitDefine);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 64:
if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_4, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_5, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_6, RegState::DefineNoRead, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_7, RegState::DefineNoRead, TRI);
if (TargetRegisterInfo::isPhysicalRegister(DestReg))
MIB.addReg(DestReg, RegState::ImplicitDefine);
} else
llvm_unreachable("Unknown reg class!");
break;
default:
llvm_unreachable("Unknown regclass!");
}
}
unsigned
ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case ARM::LDRrs:
case ARM::t2LDRs: // FIXME: don't use t2LDRs to access frame.
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isReg() &&
MI->getOperand(3).isImm() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::LDRi12:
case ARM::t2LDRi12:
case ARM::tLDRspi:
case ARM::VLDRD:
case ARM::VLDRS:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::VLD1q64:
case ARM::VLD1d64TPseudo:
case ARM::VLD1d64QPseudo:
if (MI->getOperand(1).isFI() &&
MI->getOperand(0).getSubReg() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::VLDMQIA:
if (MI->getOperand(1).isFI() &&
MI->getOperand(0).getSubReg() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned ARMBaseInstrInfo::isLoadFromStackSlotPostFE(const MachineInstr *MI,
int &FrameIndex) const {
const MachineMemOperand *Dummy;
return MI->mayLoad() && hasLoadFromStackSlot(MI, Dummy, FrameIndex);
}
/// \brief Expands MEMCPY to either LDMIA/STMIA or LDMIA_UPD/STMID_UPD
/// depending on whether the result is used.
void ARMBaseInstrInfo::expandMEMCPY(MachineBasicBlock::iterator MBBI) const {
bool isThumb1 = Subtarget.isThumb1Only();
bool isThumb2 = Subtarget.isThumb2();
const ARMBaseInstrInfo *TII = Subtarget.getInstrInfo();
MachineInstr *MI = MBBI;
DebugLoc dl = MI->getDebugLoc();
MachineBasicBlock *BB = MI->getParent();
MachineInstrBuilder LDM, STM;
if (isThumb1 || !MI->getOperand(1).isDead()) {
LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA_UPD
: isThumb1 ? ARM::tLDMIA_UPD
: ARM::LDMIA_UPD))
.addOperand(MI->getOperand(1));
} else {
LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA : ARM::LDMIA));
}
if (isThumb1 || !MI->getOperand(0).isDead()) {
STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA_UPD
: isThumb1 ? ARM::tSTMIA_UPD
: ARM::STMIA_UPD))
.addOperand(MI->getOperand(0));
} else {
STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA : ARM::STMIA));
}
AddDefaultPred(LDM.addOperand(MI->getOperand(3)));
AddDefaultPred(STM.addOperand(MI->getOperand(2)));
// Sort the scratch registers into ascending order.
const TargetRegisterInfo &TRI = getRegisterInfo();
llvm::SmallVector<unsigned, 6> ScratchRegs;
for(unsigned I = 5; I < MI->getNumOperands(); ++I)
ScratchRegs.push_back(MI->getOperand(I).getReg());
std::sort(ScratchRegs.begin(), ScratchRegs.end(),
[&TRI](const unsigned &Reg1,
const unsigned &Reg2) -> bool {
return TRI.getEncodingValue(Reg1) <
TRI.getEncodingValue(Reg2);
});
for (const auto &Reg : ScratchRegs) {
LDM.addReg(Reg, RegState::Define);
STM.addReg(Reg, RegState::Kill);
}
BB->erase(MBBI);
}
bool
ARMBaseInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
MachineFunction &MF = *MI->getParent()->getParent();
Reloc::Model RM = MF.getTarget().getRelocationModel();
if (MI->getOpcode() == TargetOpcode::LOAD_STACK_GUARD) {
assert(getSubtarget().getTargetTriple().isOSBinFormatMachO() &&
"LOAD_STACK_GUARD currently supported only for MachO.");
expandLoadStackGuard(MI, RM);
MI->getParent()->erase(MI);
return true;
}
if (MI->getOpcode() == ARM::MEMCPY) {
expandMEMCPY(MI);
return true;
}
// This hook gets to expand COPY instructions before they become
// copyPhysReg() calls. Look for VMOVS instructions that can legally be
// widened to VMOVD. We prefer the VMOVD when possible because it may be
// changed into a VORR that can go down the NEON pipeline.
if (!WidenVMOVS || !MI->isCopy() || Subtarget.isCortexA15() ||
Subtarget.isFPOnlySP())
return false;
// Look for a copy between even S-registers. That is where we keep floats
// when using NEON v2f32 instructions for f32 arithmetic.
unsigned DstRegS = MI->getOperand(0).getReg();
unsigned SrcRegS = MI->getOperand(1).getReg();
if (!ARM::SPRRegClass.contains(DstRegS, SrcRegS))
return false;
const TargetRegisterInfo *TRI = &getRegisterInfo();
unsigned DstRegD = TRI->getMatchingSuperReg(DstRegS, ARM::ssub_0,
&ARM::DPRRegClass);
unsigned SrcRegD = TRI->getMatchingSuperReg(SrcRegS, ARM::ssub_0,
&ARM::DPRRegClass);
if (!DstRegD || !SrcRegD)
return false;
// We want to widen this into a DstRegD = VMOVD SrcRegD copy. This is only
// legal if the COPY already defines the full DstRegD, and it isn't a
// sub-register insertion.
if (!MI->definesRegister(DstRegD, TRI) || MI->readsRegister(DstRegD, TRI))
return false;
// A dead copy shouldn't show up here, but reject it just in case.
if (MI->getOperand(0).isDead())
return false;
// All clear, widen the COPY.
DEBUG(dbgs() << "widening: " << *MI);
MachineInstrBuilder MIB(*MI->getParent()->getParent(), MI);
// Get rid of the old <imp-def> of DstRegD. Leave it if it defines a Q-reg
// or some other super-register.
int ImpDefIdx = MI->findRegisterDefOperandIdx(DstRegD);
if (ImpDefIdx != -1)
MI->RemoveOperand(ImpDefIdx);
// Change the opcode and operands.
MI->setDesc(get(ARM::VMOVD));
MI->getOperand(0).setReg(DstRegD);
MI->getOperand(1).setReg(SrcRegD);
AddDefaultPred(MIB);
// We are now reading SrcRegD instead of SrcRegS. This may upset the
// register scavenger and machine verifier, so we need to indicate that we
// are reading an undefined value from SrcRegD, but a proper value from
// SrcRegS.
MI->getOperand(1).setIsUndef();
MIB.addReg(SrcRegS, RegState::Implicit);
// SrcRegD may actually contain an unrelated value in the ssub_1
// sub-register. Don't kill it. Only kill the ssub_0 sub-register.
if (MI->getOperand(1).isKill()) {
MI->getOperand(1).setIsKill(false);
MI->addRegisterKilled(SrcRegS, TRI, true);
}
DEBUG(dbgs() << "replaced by: " << *MI);
return true;
}
/// Create a copy of a const pool value. Update CPI to the new index and return
/// the label UID.
static unsigned duplicateCPV(MachineFunction &MF, unsigned &CPI) {
MachineConstantPool *MCP = MF.getConstantPool();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
assert(MCPE.isMachineConstantPoolEntry() &&
"Expecting a machine constantpool entry!");
ARMConstantPoolValue *ACPV =
static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
unsigned PCLabelId = AFI->createPICLabelUId();
ARMConstantPoolValue *NewCPV = nullptr;
// FIXME: The below assumes PIC relocation model and that the function
// is Thumb mode (t1 or t2). PCAdjustment would be 8 for ARM mode PIC, and
// zero for non-PIC in ARM or Thumb. The callers are all of thumb LDR
// instructions, so that's probably OK, but is PIC always correct when
// we get here?
if (ACPV->isGlobalValue())
NewCPV = ARMConstantPoolConstant::Create(
cast<ARMConstantPoolConstant>(ACPV)->getGV(), PCLabelId, ARMCP::CPValue,
4, ACPV->getModifier(), ACPV->mustAddCurrentAddress());
else if (ACPV->isExtSymbol())
NewCPV = ARMConstantPoolSymbol::
Create(MF.getFunction()->getContext(),
cast<ARMConstantPoolSymbol>(ACPV)->getSymbol(), PCLabelId, 4);
else if (ACPV->isBlockAddress())
NewCPV = ARMConstantPoolConstant::
Create(cast<ARMConstantPoolConstant>(ACPV)->getBlockAddress(), PCLabelId,
ARMCP::CPBlockAddress, 4);
else if (ACPV->isLSDA())
NewCPV = ARMConstantPoolConstant::Create(MF.getFunction(), PCLabelId,
ARMCP::CPLSDA, 4);
else if (ACPV->isMachineBasicBlock())
NewCPV = ARMConstantPoolMBB::
Create(MF.getFunction()->getContext(),
cast<ARMConstantPoolMBB>(ACPV)->getMBB(), PCLabelId, 4);
else
llvm_unreachable("Unexpected ARM constantpool value type!!");
CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
return PCLabelId;
}
void ARMBaseInstrInfo::
reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SubIdx,
const MachineInstr *Orig,
const TargetRegisterInfo &TRI) const {
unsigned Opcode = Orig->getOpcode();
switch (Opcode) {
default: {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
MI->substituteRegister(Orig->getOperand(0).getReg(), DestReg, SubIdx, TRI);
MBB.insert(I, MI);
break;
}
case ARM::tLDRpci_pic:
case ARM::t2LDRpci_pic: {
MachineFunction &MF = *MBB.getParent();
unsigned CPI = Orig->getOperand(1).getIndex();
unsigned PCLabelId = duplicateCPV(MF, CPI);
MachineInstrBuilder MIB = BuildMI(MBB, I, Orig->getDebugLoc(), get(Opcode),
DestReg)
.addConstantPoolIndex(CPI).addImm(PCLabelId);
MIB->setMemRefs(Orig->memoperands_begin(), Orig->memoperands_end());
break;
}
}
}
MachineInstr *
ARMBaseInstrInfo::duplicate(MachineInstr *Orig, MachineFunction &MF) const {
MachineInstr *MI = TargetInstrInfo::duplicate(Orig, MF);
switch(Orig->getOpcode()) {
case ARM::tLDRpci_pic:
case ARM::t2LDRpci_pic: {
unsigned CPI = Orig->getOperand(1).getIndex();
unsigned PCLabelId = duplicateCPV(MF, CPI);
Orig->getOperand(1).setIndex(CPI);
Orig->getOperand(2).setImm(PCLabelId);
break;
}
}
return MI;
}
bool ARMBaseInstrInfo::produceSameValue(const MachineInstr *MI0,
const MachineInstr *MI1,
const MachineRegisterInfo *MRI) const {
unsigned Opcode = MI0->getOpcode();
if (Opcode == ARM::t2LDRpci ||
Opcode == ARM::t2LDRpci_pic ||
Opcode == ARM::tLDRpci ||
Opcode == ARM::tLDRpci_pic ||
Opcode == ARM::LDRLIT_ga_pcrel ||
Opcode == ARM::LDRLIT_ga_pcrel_ldr ||
Opcode == ARM::tLDRLIT_ga_pcrel ||
Opcode == ARM::MOV_ga_pcrel ||
Opcode == ARM::MOV_ga_pcrel_ldr ||
Opcode == ARM::t2MOV_ga_pcrel) {
if (MI1->getOpcode() != Opcode)
return false;
if (MI0->getNumOperands() != MI1->getNumOperands())
return false;
const MachineOperand &MO0 = MI0->getOperand(1);
const MachineOperand &MO1 = MI1->getOperand(1);
if (MO0.getOffset() != MO1.getOffset())
return false;
if (Opcode == ARM::LDRLIT_ga_pcrel ||
Opcode == ARM::LDRLIT_ga_pcrel_ldr ||
Opcode == ARM::tLDRLIT_ga_pcrel ||
Opcode == ARM::MOV_ga_pcrel ||
Opcode == ARM::MOV_ga_pcrel_ldr ||
Opcode == ARM::t2MOV_ga_pcrel)
// Ignore the PC labels.
return MO0.getGlobal() == MO1.getGlobal();
const MachineFunction *MF = MI0->getParent()->getParent();
const MachineConstantPool *MCP = MF->getConstantPool();
int CPI0 = MO0.getIndex();
int CPI1 = MO1.getIndex();
const MachineConstantPoolEntry &MCPE0 = MCP->getConstants()[CPI0];
const MachineConstantPoolEntry &MCPE1 = MCP->getConstants()[CPI1];
bool isARMCP0 = MCPE0.isMachineConstantPoolEntry();
bool isARMCP1 = MCPE1.isMachineConstantPoolEntry();
if (isARMCP0 && isARMCP1) {
ARMConstantPoolValue *ACPV0 =
static_cast<ARMConstantPoolValue*>(MCPE0.Val.MachineCPVal);
ARMConstantPoolValue *ACPV1 =
static_cast<ARMConstantPoolValue*>(MCPE1.Val.MachineCPVal);
return ACPV0->hasSameValue(ACPV1);
} else if (!isARMCP0 && !isARMCP1) {
return MCPE0.Val.ConstVal == MCPE1.Val.ConstVal;
}
return false;
} else if (Opcode == ARM::PICLDR) {
if (MI1->getOpcode() != Opcode)
return false;
if (MI0->getNumOperands() != MI1->getNumOperands())
return false;
unsigned Addr0 = MI0->getOperand(1).getReg();
unsigned Addr1 = MI1->getOperand(1).getReg();
if (Addr0 != Addr1) {
if (!MRI ||
!TargetRegisterInfo::isVirtualRegister(Addr0) ||
!TargetRegisterInfo::isVirtualRegister(Addr1))
return false;
// This assumes SSA form.
MachineInstr *Def0 = MRI->getVRegDef(Addr0);
MachineInstr *Def1 = MRI->getVRegDef(Addr1);
// Check if the loaded value, e.g. a constantpool of a global address, are
// the same.
if (!produceSameValue(Def0, Def1, MRI))
return false;
}
for (unsigned i = 3, e = MI0->getNumOperands(); i != e; ++i) {
// %vreg12<def> = PICLDR %vreg11, 0, pred:14, pred:%noreg
const MachineOperand &MO0 = MI0->getOperand(i);
const MachineOperand &MO1 = MI1->getOperand(i);
if (!MO0.isIdenticalTo(MO1))
return false;
}
return true;
}
return MI0->isIdenticalTo(*MI1, MachineInstr::IgnoreVRegDefs);
}
/// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler to
/// determine if two loads are loading from the same base address. It should
/// only return true if the base pointers are the same and the only differences
/// between the two addresses is the offset. It also returns the offsets by
/// reference.
///
/// FIXME: remove this in favor of the MachineInstr interface once pre-RA-sched
/// is permanently disabled.
bool ARMBaseInstrInfo::areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2,
int64_t &Offset1,
int64_t &Offset2) const {
// Don't worry about Thumb: just ARM and Thumb2.
if (Subtarget.isThumb1Only()) return false;
if (!Load1->isMachineOpcode() || !Load2->isMachineOpcode())
return false;
switch (Load1->getMachineOpcode()) {
default:
return false;
case ARM::LDRi12:
case ARM::LDRBi12:
case ARM::LDRD:
case ARM::LDRH:
case ARM::LDRSB:
case ARM::LDRSH:
case ARM::VLDRD:
case ARM::VLDRS:
case ARM::t2LDRi8:
case ARM::t2LDRBi8:
case ARM::t2LDRDi8:
case ARM::t2LDRSHi8:
case ARM::t2LDRi12:
case ARM::t2LDRBi12:
case ARM::t2LDRSHi12:
break;
}
switch (Load2->getMachineOpcode()) {
default:
return false;
case ARM::LDRi12:
case ARM::LDRBi12:
case ARM::LDRD:
case ARM::LDRH:
case ARM::LDRSB:
case ARM::LDRSH:
case ARM::VLDRD:
case ARM::VLDRS:
case ARM::t2LDRi8:
case ARM::t2LDRBi8:
case ARM::t2LDRSHi8:
case ARM::t2LDRi12:
case ARM::t2LDRBi12:
case ARM::t2LDRSHi12:
break;
}
// Check if base addresses and chain operands match.
if (Load1->getOperand(0) != Load2->getOperand(0) ||
Load1->getOperand(4) != Load2->getOperand(4))
return false;
// Index should be Reg0.
if (Load1->getOperand(3) != Load2->getOperand(3))
return false;
// Determine the offsets.
if (isa<ConstantSDNode>(Load1->getOperand(1)) &&
isa<ConstantSDNode>(Load2->getOperand(1))) {
Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getSExtValue();
Offset2 = cast<ConstantSDNode>(Load2->getOperand(1))->getSExtValue();
return true;
}
return false;
}
/// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
/// determine (in conjunction with areLoadsFromSameBasePtr) if two loads should
/// be scheduled togther. On some targets if two loads are loading from
/// addresses in the same cache line, it's better if they are scheduled
/// together. This function takes two integers that represent the load offsets
/// from the common base address. It returns true if it decides it's desirable
/// to schedule the two loads together. "NumLoads" is the number of loads that
/// have already been scheduled after Load1.
///
/// FIXME: remove this in favor of the MachineInstr interface once pre-RA-sched
/// is permanently disabled.
bool ARMBaseInstrInfo::shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
int64_t Offset1, int64_t Offset2,
unsigned NumLoads) const {
// Don't worry about Thumb: just ARM and Thumb2.
if (Subtarget.isThumb1Only()) return false;
assert(Offset2 > Offset1);
if ((Offset2 - Offset1) / 8 > 64)
return false;
// Check if the machine opcodes are different. If they are different
// then we consider them to not be of the same base address,
// EXCEPT in the case of Thumb2 byte loads where one is LDRBi8 and the other LDRBi12.
// In this case, they are considered to be the same because they are different
// encoding forms of the same basic instruction.
if ((Load1->getMachineOpcode() != Load2->getMachineOpcode()) &&
!((Load1->getMachineOpcode() == ARM::t2LDRBi8 &&
Load2->getMachineOpcode() == ARM::t2LDRBi12) ||
(Load1->getMachineOpcode() == ARM::t2LDRBi12 &&
Load2->getMachineOpcode() == ARM::t2LDRBi8)))
return false; // FIXME: overly conservative?
// Four loads in a row should be sufficient.
if (NumLoads >= 3)
return false;
return true;
}
bool ARMBaseInstrInfo::isSchedulingBoundary(const MachineInstr *MI,
const MachineBasicBlock *MBB,
const MachineFunction &MF) const {
// Debug info is never a scheduling boundary. It's necessary to be explicit
// due to the special treatment of IT instructions below, otherwise a
// dbg_value followed by an IT will result in the IT instruction being
// considered a scheduling hazard, which is wrong. It should be the actual
// instruction preceding the dbg_value instruction(s), just like it is
// when debug info is not present.
if (MI->isDebugValue())
return false;
// Terminators and labels can't be scheduled around.
if (MI->isTerminator() || MI->isPosition())
return true;
// Treat the start of the IT block as a scheduling boundary, but schedule
// t2IT along with all instructions following it.
// FIXME: This is a big hammer. But the alternative is to add all potential
// true and anti dependencies to IT block instructions as implicit operands
// to the t2IT instruction. The added compile time and complexity does not
// seem worth it.
MachineBasicBlock::const_iterator I = MI;
// Make sure to skip any dbg_value instructions
while (++I != MBB->end() && I->isDebugValue())
;
if (I != MBB->end() && I->getOpcode() == ARM::t2IT)
return true;
// Don't attempt to schedule around any instruction that defines
// a stack-oriented pointer, as it's unlikely to be profitable. This
// saves compile time, because it doesn't require every single
// stack slot reference to depend on the instruction that does the
// modification.
// Calls don't actually change the stack pointer, even if they have imp-defs.
// No ARM calling conventions change the stack pointer. (X86 calling
// conventions sometimes do).
if (!MI->isCall() && MI->definesRegister(ARM::SP))
return true;
return false;
}
bool ARMBaseInstrInfo::
isProfitableToIfCvt(MachineBasicBlock &MBB,
unsigned NumCycles, unsigned ExtraPredCycles,
BranchProbability Probability) const {
if (!NumCycles)
return false;
// If we are optimizing for size, see if the branch in the predecessor can be
// lowered to cbn?z by the constant island lowering pass, and return false if
// so. This results in a shorter instruction sequence.
if (MBB.getParent()->getFunction()->optForSize()) {
MachineBasicBlock *Pred = *MBB.pred_begin();
if (!Pred->empty()) {
MachineInstr *LastMI = &*Pred->rbegin();
if (LastMI->getOpcode() == ARM::t2Bcc) {
MachineBasicBlock::iterator CmpMI = LastMI;
if (CmpMI != Pred->begin()) {
--CmpMI;
if (CmpMI->getOpcode() == ARM::tCMPi8 ||
CmpMI->getOpcode() == ARM::t2CMPri) {
unsigned Reg = CmpMI->getOperand(0).getReg();
unsigned PredReg = 0;
ARMCC::CondCodes P = getInstrPredicate(*CmpMI, PredReg);
if (P == ARMCC::AL && CmpMI->getOperand(1).getImm() == 0 &&
isARMLowRegister(Reg))
return false;
}
}
}
}
}
// Attempt to estimate the relative costs of predication versus branching.
// Here we scale up each component of UnpredCost to avoid precision issue when
// scaling NumCycles by Probability.
const unsigned ScalingUpFactor = 1024;
unsigned UnpredCost = Probability.scale(NumCycles * ScalingUpFactor);
UnpredCost += ScalingUpFactor; // The branch itself
UnpredCost += Subtarget.getMispredictionPenalty() * ScalingUpFactor / 10;
return (NumCycles + ExtraPredCycles) * ScalingUpFactor <= UnpredCost;
}
bool ARMBaseInstrInfo::
isProfitableToIfCvt(MachineBasicBlock &TMBB,
unsigned TCycles, unsigned TExtra,
MachineBasicBlock &FMBB,
unsigned FCycles, unsigned FExtra,
BranchProbability Probability) const {
if (!TCycles || !FCycles)
return false;
// Attempt to estimate the relative costs of predication versus branching.
// Here we scale up each component of UnpredCost to avoid precision issue when
// scaling TCycles/FCycles by Probability.
const unsigned ScalingUpFactor = 1024;
unsigned TUnpredCost = Probability.scale(TCycles * ScalingUpFactor);
unsigned FUnpredCost =
Probability.getCompl().scale(FCycles * ScalingUpFactor);
unsigned UnpredCost = TUnpredCost + FUnpredCost;
UnpredCost += 1 * ScalingUpFactor; // The branch itself
UnpredCost += Subtarget.getMispredictionPenalty() * ScalingUpFactor / 10;
return (TCycles + FCycles + TExtra + FExtra) * ScalingUpFactor <= UnpredCost;
}
bool
ARMBaseInstrInfo::isProfitableToUnpredicate(MachineBasicBlock &TMBB,
MachineBasicBlock &FMBB) const {
// Reduce false anti-dependencies to let Swift's out-of-order execution
// engine do its thing.
return Subtarget.isSwift();
}
/// getInstrPredicate - If instruction is predicated, returns its predicate
/// condition, otherwise returns AL. It also returns the condition code
/// register by reference.
ARMCC::CondCodes llvm::getInstrPredicate(const MachineInstr &MI,
unsigned &PredReg) {
int PIdx = MI.findFirstPredOperandIdx();
if (PIdx == -1) {
PredReg = 0;
return ARMCC::AL;
}
PredReg = MI.getOperand(PIdx+1).getReg();
return (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
}
unsigned llvm::getMatchingCondBranchOpcode(unsigned Opc) {
if (Opc == ARM::B)
return ARM::Bcc;
if (Opc == ARM::tB)
return ARM::tBcc;
if (Opc == ARM::t2B)
return ARM::t2Bcc;
llvm_unreachable("Unknown unconditional branch opcode!");
}
MachineInstr *ARMBaseInstrInfo::commuteInstructionImpl(MachineInstr *MI,
bool NewMI,
unsigned OpIdx1,
unsigned OpIdx2) const {
switch (MI->getOpcode()) {
case ARM::MOVCCr:
case ARM::t2MOVCCr: {
// MOVCC can be commuted by inverting the condition.
unsigned PredReg = 0;
ARMCC::CondCodes CC = getInstrPredicate(*MI, PredReg);
// MOVCC AL can't be inverted. Shouldn't happen.
if (CC == ARMCC::AL || PredReg != ARM::CPSR)
return nullptr;
MI = TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
if (!MI)
return nullptr;
// After swapping the MOVCC operands, also invert the condition.
MI->getOperand(MI->findFirstPredOperandIdx())
.setImm(ARMCC::getOppositeCondition(CC));
return MI;
}
}
return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
/// Identify instructions that can be folded into a MOVCC instruction, and
/// return the defining instruction.
static MachineInstr *canFoldIntoMOVCC(unsigned Reg,
const MachineRegisterInfo &MRI,
const TargetInstrInfo *TII) {
if (!TargetRegisterInfo::isVirtualRegister(Reg))
return nullptr;
if (!MRI.hasOneNonDBGUse(Reg))
return nullptr;
MachineInstr *MI = MRI.getVRegDef(Reg);
if (!MI)
return nullptr;
// MI is folded into the MOVCC by predicating it.
if (!MI->isPredicable())
return nullptr;
// Check if MI has any non-dead defs or physreg uses. This also detects
// predicated instructions which will be reading CPSR.
for (unsigned i = 1, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
// Reject frame index operands, PEI can't handle the predicated pseudos.
if (MO.isFI() || MO.isCPI() || MO.isJTI())
return nullptr;
if (!MO.isReg())
continue;
// MI can't have any tied operands, that would conflict with predication.
if (MO.isTied())
return nullptr;
if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
return nullptr;
if (MO.isDef() && !MO.isDead())
return nullptr;
}
bool DontMoveAcrossStores = true;
if (!MI->isSafeToMove(/* AliasAnalysis = */ nullptr, DontMoveAcrossStores))
return nullptr;
return MI;
}
bool ARMBaseInstrInfo::analyzeSelect(const MachineInstr *MI,
SmallVectorImpl<MachineOperand> &Cond,
unsigned &TrueOp, unsigned &FalseOp,
bool &Optimizable) const {
assert((MI->getOpcode() == ARM::MOVCCr || MI->getOpcode() == ARM::t2MOVCCr) &&
"Unknown select instruction");
// MOVCC operands:
// 0: Def.
// 1: True use.
// 2: False use.
// 3: Condition code.
// 4: CPSR use.
TrueOp = 1;
FalseOp = 2;
Cond.push_back(MI->getOperand(3));
Cond.push_back(MI->getOperand(4));
// We can always fold a def.
Optimizable = true;
return false;
}
MachineInstr *
ARMBaseInstrInfo::optimizeSelect(MachineInstr *MI,
SmallPtrSetImpl<MachineInstr *> &SeenMIs,
bool PreferFalse) const {
assert((MI->getOpcode() == ARM::MOVCCr || MI->getOpcode() == ARM::t2MOVCCr) &&
"Unknown select instruction");
MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
MachineInstr *DefMI = canFoldIntoMOVCC(MI->getOperand(2).getReg(), MRI, this);
bool Invert = !DefMI;
if (!DefMI)
DefMI = canFoldIntoMOVCC(MI->getOperand(1).getReg(), MRI, this);
if (!DefMI)
return nullptr;
// Find new register class to use.
MachineOperand FalseReg = MI->getOperand(Invert ? 2 : 1);
unsigned DestReg = MI->getOperand(0).getReg();
const TargetRegisterClass *PreviousClass = MRI.getRegClass(FalseReg.getReg());
if (!MRI.constrainRegClass(DestReg, PreviousClass))
return nullptr;
// Create a new predicated version of DefMI.
// Rfalse is the first use.
MachineInstrBuilder NewMI = BuildMI(*MI->getParent(), MI, MI->getDebugLoc(),
DefMI->getDesc(), DestReg);
// Copy all the DefMI operands, excluding its (null) predicate.
const MCInstrDesc &DefDesc = DefMI->getDesc();
for (unsigned i = 1, e = DefDesc.getNumOperands();
i != e && !DefDesc.OpInfo[i].isPredicate(); ++i)
NewMI.addOperand(DefMI->getOperand(i));
unsigned CondCode = MI->getOperand(3).getImm();
if (Invert)
NewMI.addImm(ARMCC::getOppositeCondition(ARMCC::CondCodes(CondCode)));
else
NewMI.addImm(CondCode);
NewMI.addOperand(MI->getOperand(4));
// DefMI is not the -S version that sets CPSR, so add an optional %noreg.
if (NewMI->hasOptionalDef())
AddDefaultCC(NewMI);
// The output register value when the predicate is false is an implicit
// register operand tied to the first def.
// The tie makes the register allocator ensure the FalseReg is allocated the
// same register as operand 0.
FalseReg.setImplicit();
NewMI.addOperand(FalseReg);
NewMI->tieOperands(0, NewMI->getNumOperands() - 1);
// Update SeenMIs set: register newly created MI and erase removed DefMI.
SeenMIs.insert(NewMI);
SeenMIs.erase(DefMI);
// If MI is inside a loop, and DefMI is outside the loop, then kill flags on
// DefMI would be invalid when tranferred inside the loop. Checking for a
// loop is expensive, but at least remove kill flags if they are in different
// BBs.
if (DefMI->getParent() != MI->getParent())
NewMI->clearKillInfo();
// The caller will erase MI, but not DefMI.
DefMI->eraseFromParent();
return NewMI;
}
/// Map pseudo instructions that imply an 'S' bit onto real opcodes. Whether the
/// instruction is encoded with an 'S' bit is determined by the optional CPSR
/// def operand.
///
/// This will go away once we can teach tblgen how to set the optional CPSR def
/// operand itself.
struct AddSubFlagsOpcodePair {
uint16_t PseudoOpc;
uint16_t MachineOpc;
};
static const AddSubFlagsOpcodePair AddSubFlagsOpcodeMap[] = {
{ARM::ADDSri, ARM::ADDri},
{ARM::ADDSrr, ARM::ADDrr},
{ARM::ADDSrsi, ARM::ADDrsi},
{ARM::ADDSrsr, ARM::ADDrsr},
{ARM::SUBSri, ARM::SUBri},
{ARM::SUBSrr, ARM::SUBrr},
{ARM::SUBSrsi, ARM::SUBrsi},
{ARM::SUBSrsr, ARM::SUBrsr},
{ARM::RSBSri, ARM::RSBri},
{ARM::RSBSrsi, ARM::RSBrsi},
{ARM::RSBSrsr, ARM::RSBrsr},
{ARM::t2ADDSri, ARM::t2ADDri},
{ARM::t2ADDSrr, ARM::t2ADDrr},
{ARM::t2ADDSrs, ARM::t2ADDrs},
{ARM::t2SUBSri, ARM::t2SUBri},
{ARM::t2SUBSrr, ARM::t2SUBrr},
{ARM::t2SUBSrs, ARM::t2SUBrs},
{ARM::t2RSBSri, ARM::t2RSBri},
{ARM::t2RSBSrs, ARM::t2RSBrs},
};
unsigned llvm::convertAddSubFlagsOpcode(unsigned OldOpc) {
for (unsigned i = 0, e = array_lengthof(AddSubFlagsOpcodeMap); i != e; ++i)
if (OldOpc == AddSubFlagsOpcodeMap[i].PseudoOpc)
return AddSubFlagsOpcodeMap[i].MachineOpc;
return 0;
}
void llvm::emitARMRegPlusImmediate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
const DebugLoc &dl, unsigned DestReg,
unsigned BaseReg, int NumBytes,
ARMCC::CondCodes Pred, unsigned PredReg,
const ARMBaseInstrInfo &TII,
unsigned MIFlags) {
if (NumBytes == 0 && DestReg != BaseReg) {
BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), DestReg)
.addReg(BaseReg, RegState::Kill)
.addImm((unsigned)Pred).addReg(PredReg).addReg(0)
.setMIFlags(MIFlags);
return;
}
bool isSub = NumBytes < 0;
if (isSub) NumBytes = -NumBytes;
while (NumBytes) {
unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
assert(ThisVal && "Didn't extract field correctly");
// We will handle these bits from offset, clear them.
NumBytes &= ~ThisVal;
assert(ARM_AM::getSOImmVal(ThisVal) != -1 && "Bit extraction didn't work?");
// Build the new ADD / SUB.
unsigned Opc = isSub ? ARM::SUBri : ARM::ADDri;
BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
.addReg(BaseReg, RegState::Kill).addImm(ThisVal)
.addImm((unsigned)Pred).addReg(PredReg).addReg(0)
.setMIFlags(MIFlags);
BaseReg = DestReg;
}
}
bool llvm::tryFoldSPUpdateIntoPushPop(const ARMSubtarget &Subtarget,
MachineFunction &MF, MachineInstr *MI,
unsigned NumBytes) {
// This optimisation potentially adds lots of load and store
// micro-operations, it's only really a great benefit to code-size.
if (!MF.getFunction()->optForMinSize())
return false;
// If only one register is pushed/popped, LLVM can use an LDR/STR
// instead. We can't modify those so make sure we're dealing with an
// instruction we understand.
bool IsPop = isPopOpcode(MI->getOpcode());
bool IsPush = isPushOpcode(MI->getOpcode());
if (!IsPush && !IsPop)
return false;
bool IsVFPPushPop = MI->getOpcode() == ARM::VSTMDDB_UPD ||
MI->getOpcode() == ARM::VLDMDIA_UPD;
bool IsT1PushPop = MI->getOpcode() == ARM::tPUSH ||
MI->getOpcode() == ARM::tPOP ||
MI->getOpcode() == ARM::tPOP_RET;
assert((IsT1PushPop || (MI->getOperand(0).getReg() == ARM::SP &&
MI->getOperand(1).getReg() == ARM::SP)) &&
"trying to fold sp update into non-sp-updating push/pop");
// The VFP push & pop act on D-registers, so we can only fold an adjustment
// by a multiple of 8 bytes in correctly. Similarly rN is 4-bytes. Don't try
// if this is violated.
if (NumBytes % (IsVFPPushPop ? 8 : 4) != 0)
return false;
// ARM and Thumb2 push/pop insts have explicit "sp, sp" operands (+
// pred) so the list starts at 4. Thumb1 starts after the predicate.
int RegListIdx = IsT1PushPop ? 2 : 4;
// Calculate the space we'll need in terms of registers.
unsigned FirstReg = MI->getOperand(RegListIdx).getReg();
unsigned RD0Reg, RegsNeeded;
if (IsVFPPushPop) {
RD0Reg = ARM::D0;
RegsNeeded = NumBytes / 8;
} else {
RD0Reg = ARM::R0;
RegsNeeded = NumBytes / 4;
}
// We're going to have to strip all list operands off before
// re-adding them since the order matters, so save the existing ones
// for later.
SmallVector<MachineOperand, 4> RegList;
for (int i = MI->getNumOperands() - 1; i >= RegListIdx; --i)
RegList.push_back(MI->getOperand(i));
const TargetRegisterInfo *TRI = MF.getRegInfo().getTargetRegisterInfo();
const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
// Now try to find enough space in the reglist to allocate NumBytes.
for (unsigned CurReg = FirstReg - 1; CurReg >= RD0Reg && RegsNeeded;
--CurReg) {
if (!IsPop) {
// Pushing any register is completely harmless, mark the
// register involved as undef since we don't care about it in
// the slightest.
RegList.push_back(MachineOperand::CreateReg(CurReg, false, false,
false, false, true));
--RegsNeeded;
continue;
}
// However, we can only pop an extra register if it's not live. For
// registers live within the function we might clobber a return value
// register; the other way a register can be live here is if it's
// callee-saved.
if (isCalleeSavedRegister(CurReg, CSRegs) ||
MI->getParent()->computeRegisterLiveness(TRI, CurReg, MI) !=
MachineBasicBlock::LQR_Dead) {
// VFP pops don't allow holes in the register list, so any skip is fatal
// for our transformation. GPR pops do, so we should just keep looking.
if (IsVFPPushPop)
return false;
else
continue;
}
// Mark the unimportant registers as <def,dead> in the POP.
RegList.push_back(MachineOperand::CreateReg(CurReg, true, false, false,
true));
--RegsNeeded;
}
if (RegsNeeded > 0)
return false;
// Finally we know we can profitably perform the optimisation so go
// ahead: strip all existing registers off and add them back again
// in the right order.
for (int i = MI->getNumOperands() - 1; i >= RegListIdx; --i)
MI->RemoveOperand(i);
// Add the complete list back in.
MachineInstrBuilder MIB(MF, &*MI);
for (int i = RegList.size() - 1; i >= 0; --i)
MIB.addOperand(RegList[i]);
return true;
}
bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
unsigned FrameReg, int &Offset,
const ARMBaseInstrInfo &TII) {
unsigned Opcode = MI.getOpcode();
const MCInstrDesc &Desc = MI.getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
bool isSub = false;
// Memory operands in inline assembly always use AddrMode2.
if (Opcode == ARM::INLINEASM)
AddrMode = ARMII::AddrMode2;
if (Opcode == ARM::ADDri) {
Offset += MI.getOperand(FrameRegIdx+1).getImm();
if (Offset == 0) {
// Turn it into a move.
MI.setDesc(TII.get(ARM::MOVr));
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
MI.RemoveOperand(FrameRegIdx+1);
Offset = 0;
return true;
} else if (Offset < 0) {
Offset = -Offset;
isSub = true;
MI.setDesc(TII.get(ARM::SUBri));
}
// Common case: small offset, fits into instruction.
if (ARM_AM::getSOImmVal(Offset) != -1) {
// Replace the FrameIndex with sp / fp
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
Offset = 0;
return true;
}
// Otherwise, pull as much of the immedidate into this ADDri/SUBri
// as possible.
unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
// We will handle these bits from offset, clear them.
Offset &= ~ThisImmVal;
// Get the properly encoded SOImmVal field.
assert(ARM_AM::getSOImmVal(ThisImmVal) != -1 &&
"Bit extraction didn't work?");
MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
} else {
unsigned ImmIdx = 0;
int InstrOffs = 0;
unsigned NumBits = 0;
unsigned Scale = 1;
switch (AddrMode) {
case ARMII::AddrMode_i12: {
ImmIdx = FrameRegIdx + 1;
InstrOffs = MI.getOperand(ImmIdx).getImm();
NumBits = 12;
break;
}
case ARMII::AddrMode2: {
ImmIdx = FrameRegIdx+2;
InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 12;
break;
}
case ARMII::AddrMode3: {
ImmIdx = FrameRegIdx+2;
InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 8;
break;
}
case ARMII::AddrMode4:
case ARMII::AddrMode6:
// Can't fold any offset even if it's zero.
return false;
case ARMII::AddrMode5: {
ImmIdx = FrameRegIdx+1;
InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 8;
Scale = 4;
break;
}
default:
llvm_unreachable("Unsupported addressing mode!");
}
Offset += InstrOffs * Scale;
assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
if (Offset < 0) {
Offset = -Offset;
isSub = true;
}
// Attempt to fold address comp. if opcode has offset bits
if (NumBits > 0) {
// Common case: small offset, fits into instruction.
MachineOperand &ImmOp = MI.getOperand(ImmIdx);
int ImmedOffset = Offset / Scale;
unsigned Mask = (1 << NumBits) - 1;
if ((unsigned)Offset <= Mask * Scale) {
// Replace the FrameIndex with sp
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
// FIXME: When addrmode2 goes away, this will simplify (like the
// T2 version), as the LDR.i12 versions don't need the encoding
// tricks for the offset value.
if (isSub) {
if (AddrMode == ARMII::AddrMode_i12)
ImmedOffset = -ImmedOffset;
else
ImmedOffset |= 1 << NumBits;
}
ImmOp.ChangeToImmediate(ImmedOffset);
Offset = 0;
return true;
}
// Otherwise, it didn't fit. Pull in what we can to simplify the immed.
ImmedOffset = ImmedOffset & Mask;
if (isSub) {
if (AddrMode == ARMII::AddrMode_i12)
ImmedOffset = -ImmedOffset;
else
ImmedOffset |= 1 << NumBits;
}
ImmOp.ChangeToImmediate(ImmedOffset);
Offset &= ~(Mask*Scale);
}
}
Offset = (isSub) ? -Offset : Offset;
return Offset == 0;
}
/// analyzeCompare - For a comparison instruction, return the source registers
/// in SrcReg and SrcReg2 if having two register operands, and the value it
/// compares against in CmpValue. Return true if the comparison instruction
/// can be analyzed.
bool ARMBaseInstrInfo::
analyzeCompare(const MachineInstr *MI, unsigned &SrcReg, unsigned &SrcReg2,
int &CmpMask, int &CmpValue) const {
switch (MI->getOpcode()) {
default: break;
case ARM::CMPri:
case ARM::t2CMPri:
SrcReg = MI->getOperand(0).getReg();
SrcReg2 = 0;
CmpMask = ~0;
CmpValue = MI->getOperand(1).getImm();
return true;
case ARM::CMPrr:
case ARM::t2CMPrr:
SrcReg = MI->getOperand(0).getReg();
SrcReg2 = MI->getOperand(1).getReg();
CmpMask = ~0;
CmpValue = 0;
return true;
case ARM::TSTri:
case ARM::t2TSTri:
SrcReg = MI->getOperand(0).getReg();
SrcReg2 = 0;
CmpMask = MI->getOperand(1).getImm();
CmpValue = 0;
return true;
}
return false;
}
/// isSuitableForMask - Identify a suitable 'and' instruction that
/// operates on the given source register and applies the same mask
/// as a 'tst' instruction. Provide a limited look-through for copies.
/// When successful, MI will hold the found instruction.
static bool isSuitableForMask(MachineInstr *&MI, unsigned SrcReg,
int CmpMask, bool CommonUse) {
switch (MI->getOpcode()) {
case ARM::ANDri:
case ARM::t2ANDri:
if (CmpMask != MI->getOperand(2).getImm())
return false;
if (SrcReg == MI->getOperand(CommonUse ? 1 : 0).getReg())
return true;
break;
}
return false;
}
/// getSwappedCondition - assume the flags are set by MI(a,b), return
/// the condition code if we modify the instructions such that flags are
/// set by MI(b,a).
inline static ARMCC::CondCodes getSwappedCondition(ARMCC::CondCodes CC) {
switch (CC) {
default: return ARMCC::AL;
case ARMCC::EQ: return ARMCC::EQ;
case ARMCC::NE: return ARMCC::NE;
case ARMCC::HS: return ARMCC::LS;
case ARMCC::LO: return ARMCC::HI;
case ARMCC::HI: return ARMCC::LO;
case ARMCC::LS: return ARMCC::HS;
case ARMCC::GE: return ARMCC::LE;
case ARMCC::LT: return ARMCC::GT;
case ARMCC::GT: return ARMCC::LT;
case ARMCC::LE: return ARMCC::GE;
}
}
/// isRedundantFlagInstr - check whether the first instruction, whose only
/// purpose is to update flags, can be made redundant.
/// CMPrr can be made redundant by SUBrr if the operands are the same.
/// CMPri can be made redundant by SUBri if the operands are the same.
/// This function can be extended later on.
inline static bool isRedundantFlagInstr(MachineInstr *CmpI, unsigned SrcReg,
unsigned SrcReg2, int ImmValue,
MachineInstr *OI) {
if ((CmpI->getOpcode() == ARM::CMPrr ||
CmpI->getOpcode() == ARM::t2CMPrr) &&
(OI->getOpcode() == ARM::SUBrr ||
OI->getOpcode() == ARM::t2SUBrr) &&
((OI->getOperand(1).getReg() == SrcReg &&
OI->getOperand(2).getReg() == SrcReg2) ||
(OI->getOperand(1).getReg() == SrcReg2 &&
OI->getOperand(2).getReg() == SrcReg)))
return true;
if ((CmpI->getOpcode() == ARM::CMPri ||
CmpI->getOpcode() == ARM::t2CMPri) &&
(OI->getOpcode() == ARM::SUBri ||
OI->getOpcode() == ARM::t2SUBri) &&
OI->getOperand(1).getReg() == SrcReg &&
OI->getOperand(2).getImm() == ImmValue)
return true;
return false;
}
/// optimizeCompareInstr - Convert the instruction supplying the argument to the
/// comparison into one that sets the zero bit in the flags register;
/// Remove a redundant Compare instruction if an earlier instruction can set the
/// flags in the same way as Compare.
/// E.g. SUBrr(r1,r2) and CMPrr(r1,r2). We also handle the case where two
/// operands are swapped: SUBrr(r1,r2) and CMPrr(r2,r1), by updating the
/// condition code of instructions which use the flags.
bool ARMBaseInstrInfo::
optimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg, unsigned SrcReg2,
int CmpMask, int CmpValue,
const MachineRegisterInfo *MRI) const {
// Get the unique definition of SrcReg.
MachineInstr *MI = MRI->getUniqueVRegDef(SrcReg);
if (!MI) return false;
// Masked compares sometimes use the same register as the corresponding 'and'.
if (CmpMask != ~0) {
if (!isSuitableForMask(MI, SrcReg, CmpMask, false) || isPredicated(*MI)) {
MI = nullptr;
for (MachineRegisterInfo::use_instr_iterator
UI = MRI->use_instr_begin(SrcReg), UE = MRI->use_instr_end();
UI != UE; ++UI) {
if (UI->getParent() != CmpInstr->getParent()) continue;
MachineInstr *PotentialAND = &*UI;
if (!isSuitableForMask(PotentialAND, SrcReg, CmpMask, true) ||
isPredicated(*PotentialAND))
continue;
MI = PotentialAND;
break;
}
if (!MI) return false;
}
}
// Get ready to iterate backward from CmpInstr.
MachineBasicBlock::iterator I = CmpInstr, E = MI,
B = CmpInstr->getParent()->begin();
// Early exit if CmpInstr is at the beginning of the BB.
if (I == B) return false;
// There are two possible candidates which can be changed to set CPSR:
// One is MI, the other is a SUB instruction.
// For CMPrr(r1,r2), we are looking for SUB(r1,r2) or SUB(r2,r1).
// For CMPri(r1, CmpValue), we are looking for SUBri(r1, CmpValue).
MachineInstr *Sub = nullptr;
if (SrcReg2 != 0)
// MI is not a candidate for CMPrr.
MI = nullptr;
else if (MI->getParent() != CmpInstr->getParent() || CmpValue != 0) {
// Conservatively refuse to convert an instruction which isn't in the same
// BB as the comparison.
// For CMPri w/ CmpValue != 0, a Sub may still be a candidate.
// Thus we cannot return here.
if (CmpInstr->getOpcode() == ARM::CMPri ||
CmpInstr->getOpcode() == ARM::t2CMPri)
MI = nullptr;
else
return false;
}
// Check that CPSR isn't set between the comparison instruction and the one we
// want to change. At the same time, search for Sub.
const TargetRegisterInfo *TRI = &getRegisterInfo();
--I;
for (; I != E; --I) {
const MachineInstr &Instr = *I;
if (Instr.modifiesRegister(ARM::CPSR, TRI) ||
Instr.readsRegister(ARM::CPSR, TRI))
// This instruction modifies or uses CPSR after the one we want to
// change. We can't do this transformation.
return false;
// Check whether CmpInstr can be made redundant by the current instruction.
if (isRedundantFlagInstr(CmpInstr, SrcReg, SrcReg2, CmpValue, &*I)) {
Sub = &*I;
break;
}
if (I == B)
// The 'and' is below the comparison instruction.
return false;
}
// Return false if no candidates exist.
if (!MI && !Sub)
return false;
// The single candidate is called MI.
if (!MI) MI = Sub;
// We can't use a predicated instruction - it doesn't always write the flags.
if (isPredicated(*MI))
return false;
switch (MI->getOpcode()) {
default: break;
case ARM::RSBrr:
case ARM::RSBri:
case ARM::RSCrr:
case ARM::RSCri:
case ARM::ADDrr:
case ARM::ADDri:
case ARM::ADCrr:
case ARM::ADCri:
case ARM::SUBrr:
case ARM::SUBri:
case ARM::SBCrr:
case ARM::SBCri:
case ARM::t2RSBri:
case ARM::t2ADDrr:
case ARM::t2ADDri:
case ARM::t2ADCrr:
case ARM::t2ADCri:
case ARM::t2SUBrr:
case ARM::t2SUBri:
case ARM::t2SBCrr:
case ARM::t2SBCri:
case ARM::ANDrr:
case ARM::ANDri:
case ARM::t2ANDrr:
case ARM::t2ANDri:
case ARM::ORRrr:
case ARM::ORRri:
case ARM::t2ORRrr:
case ARM::t2ORRri:
case ARM::EORrr:
case ARM::EORri:
case ARM::t2EORrr:
case ARM::t2EORri: {
// Scan forward for the use of CPSR
// When checking against MI: if it's a conditional code that requires
// checking of the V bit or C bit, then this is not safe to do.
// It is safe to remove CmpInstr if CPSR is redefined or killed.
// If we are done with the basic block, we need to check whether CPSR is
// live-out.
SmallVector<std::pair<MachineOperand*, ARMCC::CondCodes>, 4>
OperandsToUpdate;
bool isSafe = false;
I = CmpInstr;
E = CmpInstr->getParent()->end();
while (!isSafe && ++I != E) {
const MachineInstr &Instr = *I;
for (unsigned IO = 0, EO = Instr.getNumOperands();
!isSafe && IO != EO; ++IO) {
const MachineOperand &MO = Instr.getOperand(IO);
if (MO.isRegMask() && MO.clobbersPhysReg(ARM::CPSR)) {
isSafe = true;
break;
}
if (!MO.isReg() || MO.getReg() != ARM::CPSR)
continue;
if (MO.isDef()) {
isSafe = true;
break;
}
// Condition code is after the operand before CPSR except for VSELs.
ARMCC::CondCodes CC;
bool IsInstrVSel = true;
switch (Instr.getOpcode()) {
default:
IsInstrVSel = false;
CC = (ARMCC::CondCodes)Instr.getOperand(IO - 1).getImm();
break;
case ARM::VSELEQD:
case ARM::VSELEQS:
CC = ARMCC::EQ;
break;
case ARM::VSELGTD:
case ARM::VSELGTS:
CC = ARMCC::GT;
break;
case ARM::VSELGED:
case ARM::VSELGES:
CC = ARMCC::GE;
break;
case ARM::VSELVSS:
case ARM::VSELVSD:
CC = ARMCC::VS;
break;
}
if (Sub) {
ARMCC::CondCodes NewCC = getSwappedCondition(CC);
if (NewCC == ARMCC::AL)
return false;
// If we have SUB(r1, r2) and CMP(r2, r1), the condition code based
// on CMP needs to be updated to be based on SUB.
// Push the condition code operands to OperandsToUpdate.
// If it is safe to remove CmpInstr, the condition code of these
// operands will be modified.
if (SrcReg2 != 0 && Sub->getOperand(1).getReg() == SrcReg2 &&
Sub->getOperand(2).getReg() == SrcReg) {
// VSel doesn't support condition code update.
if (IsInstrVSel)
return false;
OperandsToUpdate.push_back(
std::make_pair(&((*I).getOperand(IO - 1)), NewCC));
}
} else {
// No Sub, so this is x = <op> y, z; cmp x, 0.
switch (CC) {
case ARMCC::EQ: // Z
case ARMCC::NE: // Z
case ARMCC::MI: // N
case ARMCC::PL: // N
case ARMCC::AL: // none
// CPSR can be used multiple times, we should continue.
break;
case ARMCC::HS: // C
case ARMCC::LO: // C
case ARMCC::VS: // V
case ARMCC::VC: // V
case ARMCC::HI: // C Z
case ARMCC::LS: // C Z
case ARMCC::GE: // N V
case ARMCC::LT: // N V
case ARMCC::GT: // Z N V
case ARMCC::LE: // Z N V
// The instruction uses the V bit or C bit which is not safe.
return false;
}
}
}
}
// If CPSR is not killed nor re-defined, we should check whether it is
// live-out. If it is live-out, do not optimize.
if (!isSafe) {
MachineBasicBlock *MBB = CmpInstr->getParent();
for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
SE = MBB->succ_end(); SI != SE; ++SI)
if ((*SI)->isLiveIn(ARM::CPSR))
return false;
}
// Toggle the optional operand to CPSR.
MI->getOperand(5).setReg(ARM::CPSR);
MI->getOperand(5).setIsDef(true);
assert(!isPredicated(*MI) && "Can't use flags from predicated instruction");
CmpInstr->eraseFromParent();
// Modify the condition code of operands in OperandsToUpdate.
// Since we have SUB(r1, r2) and CMP(r2, r1), the condition code needs to
// be changed from r2 > r1 to r1 < r2, from r2 < r1 to r1 > r2, etc.
for (unsigned i = 0, e = OperandsToUpdate.size(); i < e; i++)
OperandsToUpdate[i].first->setImm(OperandsToUpdate[i].second);
return true;
}
}
return false;
}
bool ARMBaseInstrInfo::FoldImmediate(MachineInstr *UseMI,
MachineInstr *DefMI, unsigned Reg,
MachineRegisterInfo *MRI) const {
// Fold large immediates into add, sub, or, xor.
unsigned DefOpc = DefMI->getOpcode();
if (DefOpc != ARM::t2MOVi32imm && DefOpc != ARM::MOVi32imm)
return false;
if (!DefMI->getOperand(1).isImm())
// Could be t2MOVi32imm <ga:xx>
return false;
if (!MRI->hasOneNonDBGUse(Reg))
return false;
const MCInstrDesc &DefMCID = DefMI->getDesc();
if (DefMCID.hasOptionalDef()) {
unsigned NumOps = DefMCID.getNumOperands();
const MachineOperand &MO = DefMI->getOperand(NumOps-1);
if (MO.getReg() == ARM::CPSR && !MO.isDead())
// If DefMI defines CPSR and it is not dead, it's obviously not safe
// to delete DefMI.
return false;
}
const MCInstrDesc &UseMCID = UseMI->getDesc();
if (UseMCID.hasOptionalDef()) {
unsigned NumOps = UseMCID.getNumOperands();
if (UseMI->getOperand(NumOps-1).getReg() == ARM::CPSR)
// If the instruction sets the flag, do not attempt this optimization
// since it may change the semantics of the code.
return false;
}
unsigned UseOpc = UseMI->getOpcode();
unsigned NewUseOpc = 0;
uint32_t ImmVal = (uint32_t)DefMI->getOperand(1).getImm();
uint32_t SOImmValV1 = 0, SOImmValV2 = 0;
bool Commute = false;
switch (UseOpc) {
default: return false;
case ARM::SUBrr:
case ARM::ADDrr:
case ARM::ORRrr:
case ARM::EORrr:
case ARM::t2SUBrr:
case ARM::t2ADDrr:
case ARM::t2ORRrr:
case ARM::t2EORrr: {
Commute = UseMI->getOperand(2).getReg() != Reg;
switch (UseOpc) {
default: break;
case ARM::ADDrr:
case ARM::SUBrr: {
if (UseOpc == ARM::SUBrr && Commute)
return false;
// ADD/SUB are special because they're essentially the same operation, so
// we can handle a larger range of immediates.
if (ARM_AM::isSOImmTwoPartVal(ImmVal))
NewUseOpc = UseOpc == ARM::ADDrr ? ARM::ADDri : ARM::SUBri;
else if (ARM_AM::isSOImmTwoPartVal(-ImmVal)) {
ImmVal = -ImmVal;
NewUseOpc = UseOpc == ARM::ADDrr ? ARM::SUBri : ARM::ADDri;
} else
return false;
SOImmValV1 = (uint32_t)ARM_AM::getSOImmTwoPartFirst(ImmVal);
SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
break;
}
case ARM::ORRrr:
case ARM::EORrr: {
if (!ARM_AM::isSOImmTwoPartVal(ImmVal))
return false;
SOImmValV1 = (uint32_t)ARM_AM::getSOImmTwoPartFirst(ImmVal);
SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
switch (UseOpc) {
default: break;
case ARM::ORRrr: NewUseOpc = ARM::ORRri; break;
case ARM::EORrr: NewUseOpc = ARM::EORri; break;
}
break;
}
case ARM::t2ADDrr:
case ARM::t2SUBrr: {
if (UseOpc == ARM::t2SUBrr && Commute)
return false;
// ADD/SUB are special because they're essentially the same operation, so
// we can handle a larger range of immediates.
if (ARM_AM::isT2SOImmTwoPartVal(ImmVal))
NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2ADDri : ARM::t2SUBri;
else if (ARM_AM::isT2SOImmTwoPartVal(-ImmVal)) {
ImmVal = -ImmVal;
NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2SUBri : ARM::t2ADDri;
} else
return false;
SOImmValV1 = (uint32_t)ARM_AM::getT2SOImmTwoPartFirst(ImmVal);
SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
break;
}
case ARM::t2ORRrr:
case ARM::t2EORrr: {
if (!ARM_AM::isT2SOImmTwoPartVal(ImmVal))
return false;
SOImmValV1 = (uint32_t)ARM_AM::getT2SOImmTwoPartFirst(ImmVal);
SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
switch (UseOpc) {
default: break;
case ARM::t2ORRrr: NewUseOpc = ARM::t2ORRri; break;
case ARM::t2EORrr: NewUseOpc = ARM::t2EORri; break;
}
break;
}
}
}
}
unsigned OpIdx = Commute ? 2 : 1;
unsigned Reg1 = UseMI->getOperand(OpIdx).getReg();
bool isKill = UseMI->getOperand(OpIdx).isKill();
unsigned NewReg = MRI->createVirtualRegister(MRI->getRegClass(Reg));
AddDefaultCC(AddDefaultPred(BuildMI(*UseMI->getParent(),
UseMI, UseMI->getDebugLoc(),
get(NewUseOpc), NewReg)
.addReg(Reg1, getKillRegState(isKill))
.addImm(SOImmValV1)));
UseMI->setDesc(get(NewUseOpc));
UseMI->getOperand(1).setReg(NewReg);
UseMI->getOperand(1).setIsKill();
UseMI->getOperand(2).ChangeToImmediate(SOImmValV2);
DefMI->eraseFromParent();
return true;
}
static unsigned getNumMicroOpsSwiftLdSt(const InstrItineraryData *ItinData,
const MachineInstr *MI) {
switch (MI->getOpcode()) {
default: {
const MCInstrDesc &Desc = MI->getDesc();
int UOps = ItinData->getNumMicroOps(Desc.getSchedClass());
assert(UOps >= 0 && "bad # UOps");
return UOps;
}
case ARM::LDRrs:
case ARM::LDRBrs:
case ARM::STRrs:
case ARM::STRBrs: {
unsigned ShOpVal = MI->getOperand(3).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
return 1;
return 2;
}
case ARM::LDRH:
case ARM::STRH: {
if (!MI->getOperand(2).getReg())
return 1;
unsigned ShOpVal = MI->getOperand(3).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
return 1;
return 2;
}
case ARM::LDRSB:
case ARM::LDRSH:
return (ARM_AM::getAM3Op(MI->getOperand(3).getImm()) == ARM_AM::sub) ? 3:2;
case ARM::LDRSB_POST:
case ARM::LDRSH_POST: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rm = MI->getOperand(3).getReg();
return (Rt == Rm) ? 4 : 3;
}
case ARM::LDR_PRE_REG:
case ARM::LDRB_PRE_REG: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rm = MI->getOperand(3).getReg();
if (Rt == Rm)
return 3;
unsigned ShOpVal = MI->getOperand(4).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
return 2;
return 3;
}
case ARM::STR_PRE_REG:
case ARM::STRB_PRE_REG: {
unsigned ShOpVal = MI->getOperand(4).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
return 2;
return 3;
}
case ARM::LDRH_PRE:
case ARM::STRH_PRE: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rm = MI->getOperand(3).getReg();
if (!Rm)
return 2;
if (Rt == Rm)
return 3;
return (ARM_AM::getAM3Op(MI->getOperand(4).getImm()) == ARM_AM::sub)
? 3 : 2;
}
case ARM::LDR_POST_REG:
case ARM::LDRB_POST_REG:
case ARM::LDRH_POST: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rm = MI->getOperand(3).getReg();
return (Rt == Rm) ? 3 : 2;
}
case ARM::LDR_PRE_IMM:
case ARM::LDRB_PRE_IMM:
case ARM::LDR_POST_IMM:
case ARM::LDRB_POST_IMM:
case ARM::STRB_POST_IMM:
case ARM::STRB_POST_REG:
case ARM::STRB_PRE_IMM:
case ARM::STRH_POST:
case ARM::STR_POST_IMM:
case ARM::STR_POST_REG:
case ARM::STR_PRE_IMM:
return 2;
case ARM::LDRSB_PRE:
case ARM::LDRSH_PRE: {
unsigned Rm = MI->getOperand(3).getReg();
if (Rm == 0)
return 3;
unsigned Rt = MI->getOperand(0).getReg();
if (Rt == Rm)
return 4;
unsigned ShOpVal = MI->getOperand(4).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
return 3;
return 4;
}
case ARM::LDRD: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rn = MI->getOperand(2).getReg();
unsigned Rm = MI->getOperand(3).getReg();
if (Rm)
return (ARM_AM::getAM3Op(MI->getOperand(4).getImm()) == ARM_AM::sub) ?4:3;
return (Rt == Rn) ? 3 : 2;
}
case ARM::STRD: {
unsigned Rm = MI->getOperand(3).getReg();
if (Rm)
return (ARM_AM::getAM3Op(MI->getOperand(4).getImm()) == ARM_AM::sub) ?4:3;
return 2;
}
case ARM::LDRD_POST:
case ARM::t2LDRD_POST:
return 3;
case ARM::STRD_POST:
case ARM::t2STRD_POST:
return 4;
case ARM::LDRD_PRE: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rn = MI->getOperand(3).getReg();
unsigned Rm = MI->getOperand(4).getReg();
if (Rm)
return (ARM_AM::getAM3Op(MI->getOperand(5).getImm()) == ARM_AM::sub) ?5:4;
return (Rt == Rn) ? 4 : 3;
}
case ARM::t2LDRD_PRE: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rn = MI->getOperand(3).getReg();
return (Rt == Rn) ? 4 : 3;
}
case ARM::STRD_PRE: {
unsigned Rm = MI->getOperand(4).getReg();
if (Rm)
return (ARM_AM::getAM3Op(MI->getOperand(5).getImm()) == ARM_AM::sub) ?5:4;
return 3;
}
case ARM::t2STRD_PRE:
return 3;
case ARM::t2LDR_POST:
case ARM::t2LDRB_POST:
case ARM::t2LDRB_PRE:
case ARM::t2LDRSBi12:
case ARM::t2LDRSBi8:
case ARM::t2LDRSBpci:
case ARM::t2LDRSBs:
case ARM::t2LDRH_POST:
case ARM::t2LDRH_PRE:
case ARM::t2LDRSBT:
case ARM::t2LDRSB_POST:
case ARM::t2LDRSB_PRE:
case ARM::t2LDRSH_POST:
case ARM::t2LDRSH_PRE:
case ARM::t2LDRSHi12:
case ARM::t2LDRSHi8:
case ARM::t2LDRSHpci:
case ARM::t2LDRSHs:
return 2;
case ARM::t2LDRDi8: {
unsigned Rt = MI->getOperand(0).getReg();
unsigned Rn = MI->getOperand(2).getReg();
return (Rt == Rn) ? 3 : 2;
}
case ARM::t2STRB_POST:
case ARM::t2STRB_PRE:
case ARM::t2STRBs:
case ARM::t2STRDi8:
case ARM::t2STRH_POST:
case ARM::t2STRH_PRE:
case ARM::t2STRHs:
case ARM::t2STR_POST:
case ARM::t2STR_PRE:
case ARM::t2STRs:
return 2;
}
}
// Return the number of 32-bit words loaded by LDM or stored by STM. If this
// can't be easily determined return 0 (missing MachineMemOperand).
//
// FIXME: The current MachineInstr design does not support relying on machine
// mem operands to determine the width of a memory access. Instead, we expect
// the target to provide this information based on the instruction opcode and
// operands. However, using MachineMemOperand is the best solution now for
// two reasons:
//
// 1) getNumMicroOps tries to infer LDM memory width from the total number of MI
// operands. This is much more dangerous than using the MachineMemOperand
// sizes because CodeGen passes can insert/remove optional machine operands. In
// fact, it's totally incorrect for preRA passes and appears to be wrong for
// postRA passes as well.
//
// 2) getNumLDMAddresses is only used by the scheduling machine model and any
// machine model that calls this should handle the unknown (zero size) case.
//
// Long term, we should require a target hook that verifies MachineMemOperand
// sizes during MC lowering. That target hook should be local to MC lowering
// because we can't ensure that it is aware of other MI forms. Doing this will
// ensure that MachineMemOperands are correctly propagated through all passes.
unsigned ARMBaseInstrInfo::getNumLDMAddresses(const MachineInstr *MI) const {
unsigned Size = 0;
for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
E = MI->memoperands_end(); I != E; ++I) {
Size += (*I)->getSize();
}
return Size / 4;
}
unsigned
ARMBaseInstrInfo::getNumMicroOps(const InstrItineraryData *ItinData,
const MachineInstr *MI) const {
if (!ItinData || ItinData->isEmpty())
return 1;
const MCInstrDesc &Desc = MI->getDesc();
unsigned Class = Desc.getSchedClass();
int ItinUOps = ItinData->getNumMicroOps(Class);
if (ItinUOps >= 0) {
if (Subtarget.isSwift() && (Desc.mayLoad() || Desc.mayStore()))
return getNumMicroOpsSwiftLdSt(ItinData, MI);
return ItinUOps;
}
unsigned Opc = MI->getOpcode();
switch (Opc) {
default:
llvm_unreachable("Unexpected multi-uops instruction!");
case ARM::VLDMQIA:
case ARM::VSTMQIA:
return 2;
// The number of uOps for load / store multiple are determined by the number
// registers.
//
// On Cortex-A8, each pair of register loads / stores can be scheduled on the
// same cycle. The scheduling for the first load / store must be done
// separately by assuming the address is not 64-bit aligned.
//
// On Cortex-A9, the formula is simply (#reg / 2) + (#reg % 2). If the address
// is not 64-bit aligned, then AGU would take an extra cycle. For VFP / NEON
// load / store multiple, the formula is (#reg / 2) + (#reg % 2) + 1.
case ARM::VLDMDIA:
case ARM::VLDMDIA_UPD:
case ARM::VLDMDDB_UPD:
case ARM::VLDMSIA:
case ARM::VLDMSIA_UPD:
case ARM::VLDMSDB_UPD:
case ARM::VSTMDIA:
case ARM::VSTMDIA_UPD:
case ARM::VSTMDDB_UPD:
case ARM::VSTMSIA:
case ARM::VSTMSIA_UPD:
case ARM::VSTMSDB_UPD: {
unsigned NumRegs = MI->getNumOperands() - Desc.getNumOperands();
return (NumRegs / 2) + (NumRegs % 2) + 1;
}
case ARM::LDMIA_RET:
case ARM::LDMIA:
case ARM::LDMDA:
case ARM::LDMDB:
case ARM::LDMIB:
case ARM::LDMIA_UPD:
case ARM::LDMDA_UPD:
case ARM::LDMDB_UPD:
case ARM::LDMIB_UPD:
case ARM::STMIA:
case ARM::STMDA:
case ARM::STMDB:
case ARM::STMIB:
case ARM::STMIA_UPD:
case ARM::STMDA_UPD:
case ARM::STMDB_UPD:
case ARM::STMIB_UPD:
case ARM::tLDMIA:
case ARM::tLDMIA_UPD:
case ARM::tSTMIA_UPD:
case ARM::tPOP_RET:
case ARM::tPOP:
case ARM::tPUSH:
case ARM::t2LDMIA_RET:
case ARM::t2LDMIA:
case ARM::t2LDMDB:
case ARM::t2LDMIA_UPD:
case ARM::t2LDMDB_UPD:
case ARM::t2STMIA:
case ARM::t2STMDB:
case ARM::t2STMIA_UPD:
case ARM::t2STMDB_UPD: {
unsigned NumRegs = MI->getNumOperands() - Desc.getNumOperands() + 1;
if (Subtarget.isSwift()) {
int UOps = 1 + NumRegs; // One for address computation, one for each ld / st.
switch (Opc) {
default: break;
case ARM::VLDMDIA_UPD:
case ARM::VLDMDDB_UPD:
case ARM::VLDMSIA_UPD:
case ARM::VLDMSDB_UPD:
case ARM::VSTMDIA_UPD:
case ARM::VSTMDDB_UPD:
case ARM::VSTMSIA_UPD:
case ARM::VSTMSDB_UPD:
case ARM::LDMIA_UPD:
case ARM::LDMDA_UPD:
case ARM::LDMDB_UPD:
case ARM::LDMIB_UPD:
case ARM::STMIA_UPD:
case ARM::STMDA_UPD:
case ARM::STMDB_UPD:
case ARM::STMIB_UPD:
case ARM::tLDMIA_UPD:
case ARM::tSTMIA_UPD:
case ARM::t2LDMIA_UPD:
case ARM::t2LDMDB_UPD:
case ARM::t2STMIA_UPD:
case ARM::t2STMDB_UPD:
++UOps; // One for base register writeback.
break;
case ARM::LDMIA_RET:
case ARM::tPOP_RET:
case ARM::t2LDMIA_RET:
UOps += 2; // One for base reg wb, one for write to pc.
break;
}
return UOps;
} else if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
if (NumRegs < 4)
return 2;
// 4 registers would be issued: 2, 2.
// 5 registers would be issued: 2, 2, 1.
int A8UOps = (NumRegs / 2);
if (NumRegs % 2)
++A8UOps;
return A8UOps;
} else if (Subtarget.isLikeA9()) {
int A9UOps = (NumRegs / 2);
// If there are odd number of registers or if it's not 64-bit aligned,
// then it takes an extra AGU (Address Generation Unit) cycle.
if ((NumRegs % 2) ||
!MI->hasOneMemOperand() ||
(*MI->memoperands_begin())->getAlignment() < 8)
++A9UOps;
return A9UOps;
} else {
// Assume the worst.
return NumRegs;
}
}
}
}
int
ARMBaseInstrInfo::getVLDMDefCycle(const InstrItineraryData *ItinData,
const MCInstrDesc &DefMCID,
unsigned DefClass,
unsigned DefIdx, unsigned DefAlign) const {
int RegNo = (int)(DefIdx+1) - DefMCID.getNumOperands() + 1;
if (RegNo <= 0)
// Def is the address writeback.
return ItinData->getOperandCycle(DefClass, DefIdx);
int DefCycle;
if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
// (regno / 2) + (regno % 2) + 1
DefCycle = RegNo / 2 + 1;
if (RegNo % 2)
++DefCycle;
} else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
DefCycle = RegNo;
bool isSLoad = false;
switch (DefMCID.getOpcode()) {
default: break;
case ARM::VLDMSIA:
case ARM::VLDMSIA_UPD:
case ARM::VLDMSDB_UPD:
isSLoad = true;
break;
}
// If there are odd number of 'S' registers or if it's not 64-bit aligned,
// then it takes an extra cycle.
if ((isSLoad && (RegNo % 2)) || DefAlign < 8)
++DefCycle;
} else {
// Assume the worst.
DefCycle = RegNo + 2;
}
return DefCycle;
}
int
ARMBaseInstrInfo::getLDMDefCycle(const InstrItineraryData *ItinData,
const MCInstrDesc &DefMCID,
unsigned DefClass,
unsigned DefIdx, unsigned DefAlign) const {
int RegNo = (int)(DefIdx+1) - DefMCID.getNumOperands() + 1;
if (RegNo <= 0)
// Def is the address writeback.
return ItinData->getOperandCycle(DefClass, DefIdx);
int DefCycle;
if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
// 4 registers would be issued: 1, 2, 1.
// 5 registers would be issued: 1, 2, 2.
DefCycle = RegNo / 2;
if (DefCycle < 1)
DefCycle = 1;
// Result latency is issue cycle + 2: E2.
DefCycle += 2;
} else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
DefCycle = (RegNo / 2);
// If there are odd number of registers or if it's not 64-bit aligned,
// then it takes an extra AGU (Address Generation Unit) cycle.
if ((RegNo % 2) || DefAlign < 8)
++DefCycle;
// Result latency is AGU cycles + 2.
DefCycle += 2;
} else {
// Assume the worst.
DefCycle = RegNo + 2;
}
return DefCycle;
}
int
ARMBaseInstrInfo::getVSTMUseCycle(const InstrItineraryData *ItinData,
const MCInstrDesc &UseMCID,
unsigned UseClass,
unsigned UseIdx, unsigned UseAlign) const {
int RegNo = (int)(UseIdx+1) - UseMCID.getNumOperands() + 1;
if (RegNo <= 0)
return ItinData->getOperandCycle(UseClass, UseIdx);
int UseCycle;
if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
// (regno / 2) + (regno % 2) + 1
UseCycle = RegNo / 2 + 1;
if (RegNo % 2)
++UseCycle;
} else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
UseCycle = RegNo;
bool isSStore = false;
switch (UseMCID.getOpcode()) {
default: break;
case ARM::VSTMSIA:
case ARM::VSTMSIA_UPD:
case ARM::VSTMSDB_UPD:
isSStore = true;
break;
}
// If there are odd number of 'S' registers or if it's not 64-bit aligned,
// then it takes an extra cycle.
if ((isSStore && (RegNo % 2)) || UseAlign < 8)
++UseCycle;
} else {
// Assume the worst.
UseCycle = RegNo + 2;
}
return UseCycle;
}
int
ARMBaseInstrInfo::getSTMUseCycle(const InstrItineraryData *ItinData,
const MCInstrDesc &UseMCID,
unsigned UseClass,
unsigned UseIdx, unsigned UseAlign) const {
int RegNo = (int)(UseIdx+1) - UseMCID.getNumOperands() + 1;
if (RegNo <= 0)
return ItinData->getOperandCycle(UseClass, UseIdx);
int UseCycle;
if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
UseCycle = RegNo / 2;
if (UseCycle < 2)
UseCycle = 2;
// Read in E3.
UseCycle += 2;
} else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
UseCycle = (RegNo / 2);
// If there are odd number of registers or if it's not 64-bit aligned,
// then it takes an extra AGU (Address Generation Unit) cycle.
if ((RegNo % 2) || UseAlign < 8)
++UseCycle;
} else {
// Assume the worst.
UseCycle = 1;
}
return UseCycle;
}
int
ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
const MCInstrDesc &DefMCID,
unsigned DefIdx, unsigned DefAlign,
const MCInstrDesc &UseMCID,
unsigned UseIdx, unsigned UseAlign) const {
unsigned DefClass = DefMCID.getSchedClass();
unsigned UseClass = UseMCID.getSchedClass();
if (DefIdx < DefMCID.getNumDefs() && UseIdx < UseMCID.getNumOperands())
return ItinData->getOperandLatency(DefClass, DefIdx, UseClass, UseIdx);
// This may be a def / use of a variable_ops instruction, the operand
// latency might be determinable dynamically. Let the target try to
// figure it out.
int DefCycle = -1;
bool LdmBypass = false;
switch (DefMCID.getOpcode()) {
default:
DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
break;
case ARM::VLDMDIA:
case ARM::VLDMDIA_UPD:
case ARM::VLDMDDB_UPD:
case ARM::VLDMSIA:
case ARM::VLDMSIA_UPD:
case ARM::VLDMSDB_UPD:
DefCycle = getVLDMDefCycle(ItinData, DefMCID, DefClass, DefIdx, DefAlign);
break;
case ARM::LDMIA_RET:
case ARM::LDMIA:
case ARM::LDMDA:
case ARM::LDMDB:
case ARM::LDMIB:
case ARM::LDMIA_UPD:
case ARM::LDMDA_UPD:
case ARM::LDMDB_UPD:
case ARM::LDMIB_UPD:
case ARM::tLDMIA:
case ARM::tLDMIA_UPD:
case ARM::tPUSH:
case ARM::t2LDMIA_RET:
case ARM::t2LDMIA:
case ARM::t2LDMDB:
case ARM::t2LDMIA_UPD:
case ARM::t2LDMDB_UPD:
LdmBypass = 1;
DefCycle = getLDMDefCycle(ItinData, DefMCID, DefClass, DefIdx, DefAlign);
break;
}
if (DefCycle == -1)
// We can't seem to determine the result latency of the def, assume it's 2.
DefCycle = 2;
int UseCycle = -1;
switch (UseMCID.getOpcode()) {
default:
UseCycle = ItinData->getOperandCycle(UseClass, UseIdx);
break;
case ARM::VSTMDIA:
case ARM::VSTMDIA_UPD:
case ARM::VSTMDDB_UPD:
case ARM::VSTMSIA:
case ARM::VSTMSIA_UPD:
case ARM::VSTMSDB_UPD:
UseCycle = getVSTMUseCycle(ItinData, UseMCID, UseClass, UseIdx, UseAlign);
break;
case ARM::STMIA:
case ARM::STMDA:
case ARM::STMDB:
case ARM::STMIB:
case ARM::STMIA_UPD:
case ARM::STMDA_UPD:
case ARM::STMDB_UPD:
case ARM::STMIB_UPD:
case ARM::tSTMIA_UPD:
case ARM::tPOP_RET:
case ARM::tPOP:
case ARM::t2STMIA:
case ARM::t2STMDB:
case ARM::t2STMIA_UPD:
case ARM::t2STMDB_UPD:
UseCycle = getSTMUseCycle(ItinData, UseMCID, UseClass, UseIdx, UseAlign);
break;
}
if (UseCycle == -1)
// Assume it's read in the first stage.
UseCycle = 1;
UseCycle = DefCycle - UseCycle + 1;
if (UseCycle > 0) {
if (LdmBypass) {
// It's a variable_ops instruction so we can't use DefIdx here. Just use
// first def operand.
if (ItinData->hasPipelineForwarding(DefClass, DefMCID.getNumOperands()-1,
UseClass, UseIdx))
--UseCycle;
} else if (ItinData->hasPipelineForwarding(DefClass, DefIdx,
UseClass, UseIdx)) {
--UseCycle;
}
}
return UseCycle;
}
static const MachineInstr *getBundledDefMI(const TargetRegisterInfo *TRI,
const MachineInstr *MI, unsigned Reg,
unsigned &DefIdx, unsigned &Dist) {
Dist = 0;
MachineBasicBlock::const_iterator I = MI; ++I;
MachineBasicBlock::const_instr_iterator II = std::prev(I.getInstrIterator());
assert(II->isInsideBundle() && "Empty bundle?");
int Idx = -1;
while (II->isInsideBundle()) {
Idx = II->findRegisterDefOperandIdx(Reg, false, true, TRI);
if (Idx != -1)
break;
--II;
++Dist;
}
assert(Idx != -1 && "Cannot find bundled definition!");
DefIdx = Idx;
return &*II;
}
static const MachineInstr *getBundledUseMI(const TargetRegisterInfo *TRI,
const MachineInstr *MI, unsigned Reg,
unsigned &UseIdx, unsigned &Dist) {
Dist = 0;
MachineBasicBlock::const_instr_iterator II = ++MI->getIterator();
assert(II->isInsideBundle() && "Empty bundle?");
MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
// FIXME: This doesn't properly handle multiple uses.
int Idx = -1;
while (II != E && II->isInsideBundle()) {
Idx = II->findRegisterUseOperandIdx(Reg, false, TRI);
if (Idx != -1)
break;
if (II->getOpcode() != ARM::t2IT)
++Dist;
++II;
}
if (Idx == -1) {
Dist = 0;
return nullptr;
}
UseIdx = Idx;
return &*II;
}
/// Return the number of cycles to add to (or subtract from) the static
/// itinerary based on the def opcode and alignment. The caller will ensure that
/// adjusted latency is at least one cycle.
static int adjustDefLatency(const ARMSubtarget &Subtarget,
const MachineInstr *DefMI,
const MCInstrDesc *DefMCID, unsigned DefAlign) {
int Adjust = 0;
if (Subtarget.isCortexA8() || Subtarget.isLikeA9() || Subtarget.isCortexA7()) {
// FIXME: Shifter op hack: no shift (i.e. [r +/- r]) or [r + r << 2]
// variants are one cycle cheaper.
switch (DefMCID->getOpcode()) {
default: break;
case ARM::LDRrs:
case ARM::LDRBrs: {
unsigned ShOpVal = DefMI->getOperand(3).getImm();
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (ShImm == 0 ||
(ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
--Adjust;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs: {
// Thumb2 mode: lsl only.
unsigned ShAmt = DefMI->getOperand(3).getImm();
if (ShAmt == 0 || ShAmt == 2)
--Adjust;
break;
}
}
} else if (Subtarget.isSwift()) {
// FIXME: Properly handle all of the latency adjustments for address
// writeback.
switch (DefMCID->getOpcode()) {
default: break;
case ARM::LDRrs:
case ARM::LDRBrs: {
unsigned ShOpVal = DefMI->getOperand(3).getImm();
bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (!isSub &&
(ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
Adjust -= 2;
else if (!isSub &&
ShImm == 1 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsr)
--Adjust;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs: {
// Thumb2 mode: lsl only.
unsigned ShAmt = DefMI->getOperand(3).getImm();
if (ShAmt == 0 || ShAmt == 1 || ShAmt == 2 || ShAmt == 3)
Adjust -= 2;
break;
}
}
}
if (DefAlign < 8 && Subtarget.isLikeA9()) {
switch (DefMCID->getOpcode()) {
default: break;
case ARM::VLD1q8:
case ARM::VLD1q16:
case ARM::VLD1q32:
case ARM::VLD1q64:
case ARM::VLD1q8wb_fixed:
case ARM::VLD1q16wb_fixed:
case ARM::VLD1q32wb_fixed:
case ARM::VLD1q64wb_fixed:
case ARM::VLD1q8wb_register:
case ARM::VLD1q16wb_register:
case ARM::VLD1q32wb_register:
case ARM::VLD1q64wb_register:
case ARM::VLD2d8:
case ARM::VLD2d16:
case ARM::VLD2d32:
case ARM::VLD2q8:
case ARM::VLD2q16:
case ARM::VLD2q32:
case ARM::VLD2d8wb_fixed:
case ARM::VLD2d16wb_fixed:
case ARM::VLD2d32wb_fixed:
case ARM::VLD2q8wb_fixed:
case ARM::VLD2q16wb_fixed:
case ARM::VLD2q32wb_fixed:
case ARM::VLD2d8wb_register:
case ARM::VLD2d16wb_register:
case ARM::VLD2d32wb_register:
case ARM::VLD2q8wb_register:
case ARM::VLD2q16wb_register:
case ARM::VLD2q32wb_register:
case ARM::VLD3d8:
case ARM::VLD3d16:
case ARM::VLD3d32:
case ARM::VLD1d64T:
case ARM::VLD3d8_UPD:
case ARM::VLD3d16_UPD:
case ARM::VLD3d32_UPD:
case ARM::VLD1d64Twb_fixed:
case ARM::VLD1d64Twb_register:
case ARM::VLD3q8_UPD:
case ARM::VLD3q16_UPD:
case ARM::VLD3q32_UPD:
case ARM::VLD4d8:
case ARM::VLD4d16:
case ARM::VLD4d32:
case ARM::VLD1d64Q:
case ARM::VLD4d8_UPD:
case ARM::VLD4d16_UPD:
case ARM::VLD4d32_UPD:
case ARM::VLD1d64Qwb_fixed:
case ARM::VLD1d64Qwb_register:
case ARM::VLD4q8_UPD:
case ARM::VLD4q16_UPD:
case ARM::VLD4q32_UPD:
case ARM::VLD1DUPq8:
case ARM::VLD1DUPq16:
case ARM::VLD1DUPq32:
case ARM::VLD1DUPq8wb_fixed:
case ARM::VLD1DUPq16wb_fixed:
case ARM::VLD1DUPq32wb_fixed:
case ARM::VLD1DUPq8wb_register:
case ARM::VLD1DUPq16wb_register:
case ARM::VLD1DUPq32wb_register:
case ARM::VLD2DUPd8:
case ARM::VLD2DUPd16:
case ARM::VLD2DUPd32:
case ARM::VLD2DUPd8wb_fixed:
case ARM::VLD2DUPd16wb_fixed:
case ARM::VLD2DUPd32wb_fixed:
case ARM::VLD2DUPd8wb_register:
case ARM::VLD2DUPd16wb_register:
case ARM::VLD2DUPd32wb_register:
case ARM::VLD4DUPd8:
case ARM::VLD4DUPd16:
case ARM::VLD4DUPd32:
case ARM::VLD4DUPd8_UPD:
case ARM::VLD4DUPd16_UPD:
case ARM::VLD4DUPd32_UPD:
case ARM::VLD1LNd8:
case ARM::VLD1LNd16:
case ARM::VLD1LNd32:
case ARM::VLD1LNd8_UPD:
case ARM::VLD1LNd16_UPD:
case ARM::VLD1LNd32_UPD:
case ARM::VLD2LNd8:
case ARM::VLD2LNd16:
case ARM::VLD2LNd32:
case ARM::VLD2LNq16:
case ARM::VLD2LNq32:
case ARM::VLD2LNd8_UPD:
case ARM::VLD2LNd16_UPD:
case ARM::VLD2LNd32_UPD:
case ARM::VLD2LNq16_UPD:
case ARM::VLD2LNq32_UPD:
case ARM::VLD4LNd8:
case ARM::VLD4LNd16:
case ARM::VLD4LNd32:
case ARM::VLD4LNq16:
case ARM::VLD4LNq32:
case ARM::VLD4LNd8_UPD:
case ARM::VLD4LNd16_UPD:
case ARM::VLD4LNd32_UPD:
case ARM::VLD4LNq16_UPD:
case ARM::VLD4LNq32_UPD:
// If the address is not 64-bit aligned, the latencies of these
// instructions increases by one.
++Adjust;
break;
}
}
return Adjust;
}
int
ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
const MachineInstr *DefMI, unsigned DefIdx,
const MachineInstr *UseMI,
unsigned UseIdx) const {
// No operand latency. The caller may fall back to getInstrLatency.
if (!ItinData || ItinData->isEmpty())
return -1;
const MachineOperand &DefMO = DefMI->getOperand(DefIdx);
unsigned Reg = DefMO.getReg();
const MCInstrDesc *DefMCID = &DefMI->getDesc();
const MCInstrDesc *UseMCID = &UseMI->getDesc();
unsigned DefAdj = 0;
if (DefMI->isBundle()) {
DefMI = getBundledDefMI(&getRegisterInfo(), DefMI, Reg, DefIdx, DefAdj);
DefMCID = &DefMI->getDesc();
}
if (DefMI->isCopyLike() || DefMI->isInsertSubreg() ||
DefMI->isRegSequence() || DefMI->isImplicitDef()) {
return 1;
}
unsigned UseAdj = 0;
if (UseMI->isBundle()) {
unsigned NewUseIdx;
const MachineInstr *NewUseMI = getBundledUseMI(&getRegisterInfo(), UseMI,
Reg, NewUseIdx, UseAdj);
if (!NewUseMI)
return -1;
UseMI = NewUseMI;
UseIdx = NewUseIdx;
UseMCID = &UseMI->getDesc();
}
if (Reg == ARM::CPSR) {
if (DefMI->getOpcode() == ARM::FMSTAT) {
// fpscr -> cpsr stalls over 20 cycles on A8 (and earlier?)
return Subtarget.isLikeA9() ? 1 : 20;
}
// CPSR set and branch can be paired in the same cycle.
if (UseMI->isBranch())
return 0;
// Otherwise it takes the instruction latency (generally one).
unsigned Latency = getInstrLatency(ItinData, DefMI);
// For Thumb2 and -Os, prefer scheduling CPSR setting instruction close to
// its uses. Instructions which are otherwise scheduled between them may
// incur a code size penalty (not able to use the CPSR setting 16-bit
// instructions).
if (Latency > 0 && Subtarget.isThumb2()) {
const MachineFunction *MF = DefMI->getParent()->getParent();
// FIXME: Use Function::optForSize().
if (MF->getFunction()->hasFnAttribute(Attribute::OptimizeForSize))
--Latency;
}
return Latency;
}
if (DefMO.isImplicit() || UseMI->getOperand(UseIdx).isImplicit())
return -1;
unsigned DefAlign = DefMI->hasOneMemOperand()
? (*DefMI->memoperands_begin())->getAlignment() : 0;
unsigned UseAlign = UseMI->hasOneMemOperand()
? (*UseMI->memoperands_begin())->getAlignment() : 0;
// Get the itinerary's latency if possible, and handle variable_ops.
int Latency = getOperandLatency(ItinData, *DefMCID, DefIdx, DefAlign,
*UseMCID, UseIdx, UseAlign);
// Unable to find operand latency. The caller may resort to getInstrLatency.
if (Latency < 0)
return Latency;
// Adjust for IT block position.
int Adj = DefAdj + UseAdj;
// Adjust for dynamic def-side opcode variants not captured by the itinerary.
Adj += adjustDefLatency(Subtarget, DefMI, DefMCID, DefAlign);
if (Adj >= 0 || (int)Latency > -Adj) {
return Latency + Adj;
}
// Return the itinerary latency, which may be zero but not less than zero.
return Latency;
}
int
ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
SDNode *DefNode, unsigned DefIdx,
SDNode *UseNode, unsigned UseIdx) const {
if (!DefNode->isMachineOpcode())
return 1;
const MCInstrDesc &DefMCID = get(DefNode->getMachineOpcode());
if (isZeroCost(DefMCID.Opcode))
return 0;
if (!ItinData || ItinData->isEmpty())
return DefMCID.mayLoad() ? 3 : 1;
if (!UseNode->isMachineOpcode()) {
int Latency = ItinData->getOperandCycle(DefMCID.getSchedClass(), DefIdx);
if (Subtarget.isLikeA9() || Subtarget.isSwift())
return Latency <= 2 ? 1 : Latency - 1;
else
return Latency <= 3 ? 1 : Latency - 2;
}
const MCInstrDesc &UseMCID = get(UseNode->getMachineOpcode());
const MachineSDNode *DefMN = dyn_cast<MachineSDNode>(DefNode);
unsigned DefAlign = !DefMN->memoperands_empty()
? (*DefMN->memoperands_begin())->getAlignment() : 0;
const MachineSDNode *UseMN = dyn_cast<MachineSDNode>(UseNode);
unsigned UseAlign = !UseMN->memoperands_empty()
? (*UseMN->memoperands_begin())->getAlignment() : 0;
int Latency = getOperandLatency(ItinData, DefMCID, DefIdx, DefAlign,
UseMCID, UseIdx, UseAlign);
if (Latency > 1 &&
(Subtarget.isCortexA8() || Subtarget.isLikeA9() ||
Subtarget.isCortexA7())) {
// FIXME: Shifter op hack: no shift (i.e. [r +/- r]) or [r + r << 2]
// variants are one cycle cheaper.
switch (DefMCID.getOpcode()) {
default: break;
case ARM::LDRrs:
case ARM::LDRBrs: {
unsigned ShOpVal =
cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (ShImm == 0 ||
(ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
--Latency;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs: {
// Thumb2 mode: lsl only.
unsigned ShAmt =
cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
if (ShAmt == 0 || ShAmt == 2)
--Latency;
break;
}
}
} else if (DefIdx == 0 && Latency > 2 && Subtarget.isSwift()) {
// FIXME: Properly handle all of the latency adjustments for address
// writeback.
switch (DefMCID.getOpcode()) {
default: break;
case ARM::LDRrs:
case ARM::LDRBrs: {
unsigned ShOpVal =
cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
Latency -= 2;
else if (ShImm == 1 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsr)
--Latency;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs: {
// Thumb2 mode: lsl 0-3 only.
Latency -= 2;
break;
}
}
}
if (DefAlign < 8 && Subtarget.isLikeA9())
switch (DefMCID.getOpcode()) {
default: break;
case ARM::VLD1q8:
case ARM::VLD1q16:
case ARM::VLD1q32:
case ARM::VLD1q64:
case ARM::VLD1q8wb_register:
case ARM::VLD1q16wb_register:
case ARM::VLD1q32wb_register:
case ARM::VLD1q64wb_register:
case ARM::VLD1q8wb_fixed:
case ARM::VLD1q16wb_fixed:
case ARM::VLD1q32wb_fixed:
case ARM::VLD1q64wb_fixed:
case ARM::VLD2d8:
case ARM::VLD2d16:
case ARM::VLD2d32:
case ARM::VLD2q8Pseudo:
case ARM::VLD2q16Pseudo:
case ARM::VLD2q32Pseudo:
case ARM::VLD2d8wb_fixed:
case ARM::VLD2d16wb_fixed:
case ARM::VLD2d32wb_fixed:
case ARM::VLD2q8PseudoWB_fixed:
case ARM::VLD2q16PseudoWB_fixed:
case ARM::VLD2q32PseudoWB_fixed:
case ARM::VLD2d8wb_register:
case ARM::VLD2d16wb_register:
case ARM::VLD2d32wb_register:
case ARM::VLD2q8PseudoWB_register:
case ARM::VLD2q16PseudoWB_register:
case ARM::VLD2q32PseudoWB_register:
case ARM::VLD3d8Pseudo:
case ARM::VLD3d16Pseudo:
case ARM::VLD3d32Pseudo:
case ARM::VLD1d64TPseudo:
case ARM::VLD1d64TPseudoWB_fixed:
case ARM::VLD3d8Pseudo_UPD:
case ARM::VLD3d16Pseudo_UPD:
case ARM::VLD3d32Pseudo_UPD:
case ARM::VLD3q8Pseudo_UPD:
case ARM::VLD3q16Pseudo_UPD:
case ARM::VLD3q32Pseudo_UPD:
case ARM::VLD3q8oddPseudo:
case ARM::VLD3q16oddPseudo:
case ARM::VLD3q32oddPseudo:
case ARM::VLD3q8oddPseudo_UPD:
case ARM::VLD3q16oddPseudo_UPD:
case ARM::VLD3q32oddPseudo_UPD:
case ARM::VLD4d8Pseudo:
case ARM::VLD4d16Pseudo:
case ARM::VLD4d32Pseudo:
case ARM::VLD1d64QPseudo:
case ARM::VLD1d64QPseudoWB_fixed:
case ARM::VLD4d8Pseudo_UPD:
case ARM::VLD4d16Pseudo_UPD:
case ARM::VLD4d32Pseudo_UPD:
case ARM::VLD4q8Pseudo_UPD:
case ARM::VLD4q16Pseudo_UPD:
case ARM::VLD4q32Pseudo_UPD:
case ARM::VLD4q8oddPseudo:
case ARM::VLD4q16oddPseudo:
case ARM::VLD4q32oddPseudo:
case ARM::VLD4q8oddPseudo_UPD:
case ARM::VLD4q16oddPseudo_UPD:
case ARM::VLD4q32oddPseudo_UPD:
case ARM::VLD1DUPq8:
case ARM::VLD1DUPq16:
case ARM::VLD1DUPq32:
case ARM::VLD1DUPq8wb_fixed:
case ARM::VLD1DUPq16wb_fixed:
case ARM::VLD1DUPq32wb_fixed:
case ARM::VLD1DUPq8wb_register:
case ARM::VLD1DUPq16wb_register:
case ARM::VLD1DUPq32wb_register:
case ARM::VLD2DUPd8:
case ARM::VLD2DUPd16:
case ARM::VLD2DUPd32:
case ARM::VLD2DUPd8wb_fixed:
case ARM::VLD2DUPd16wb_fixed:
case ARM::VLD2DUPd32wb_fixed:
case ARM::VLD2DUPd8wb_register:
case ARM::VLD2DUPd16wb_register:
case ARM::VLD2DUPd32wb_register:
case ARM::VLD4DUPd8Pseudo:
case ARM::VLD4DUPd16Pseudo:
case ARM::VLD4DUPd32Pseudo:
case ARM::VLD4DUPd8Pseudo_UPD:
case ARM::VLD4DUPd16Pseudo_UPD:
case ARM::VLD4DUPd32Pseudo_UPD:
case ARM::VLD1LNq8Pseudo:
case ARM::VLD1LNq16Pseudo:
case ARM::VLD1LNq32Pseudo:
case ARM::VLD1LNq8Pseudo_UPD:
case ARM::VLD1LNq16Pseudo_UPD:
case ARM::VLD1LNq32Pseudo_UPD:
case ARM::VLD2LNd8Pseudo:
case ARM::VLD2LNd16Pseudo:
case ARM::VLD2LNd32Pseudo:
case ARM::VLD2LNq16Pseudo:
case ARM::VLD2LNq32Pseudo:
case ARM::VLD2LNd8Pseudo_UPD:
case ARM::VLD2LNd16Pseudo_UPD:
case ARM::VLD2LNd32Pseudo_UPD:
case ARM::VLD2LNq16Pseudo_UPD:
case ARM::VLD2LNq32Pseudo_UPD:
case ARM::VLD4LNd8Pseudo:
case ARM::VLD4LNd16Pseudo:
case ARM::VLD4LNd32Pseudo:
case ARM::VLD4LNq16Pseudo:
case ARM::VLD4LNq32Pseudo:
case ARM::VLD4LNd8Pseudo_UPD:
case ARM::VLD4LNd16Pseudo_UPD:
case ARM::VLD4LNd32Pseudo_UPD:
case ARM::VLD4LNq16Pseudo_UPD:
case ARM::VLD4LNq32Pseudo_UPD:
// If the address is not 64-bit aligned, the latencies of these
// instructions increases by one.
++Latency;
break;
}
return Latency;
}
unsigned ARMBaseInstrInfo::getPredicationCost(const MachineInstr &MI) const {
if (MI.isCopyLike() || MI.isInsertSubreg() || MI.isRegSequence() ||
MI.isImplicitDef())
return 0;
if (MI.isBundle())
return 0;
const MCInstrDesc &MCID = MI.getDesc();
if (MCID.isCall() || MCID.hasImplicitDefOfPhysReg(ARM::CPSR)) {
// When predicated, CPSR is an additional source operand for CPSR updating
// instructions, this apparently increases their latencies.
return 1;
}
return 0;
}
unsigned ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
const MachineInstr *MI,
unsigned *PredCost) const {
if (MI->isCopyLike() || MI->isInsertSubreg() ||
MI->isRegSequence() || MI->isImplicitDef())
return 1;
// An instruction scheduler typically runs on unbundled instructions, however
// other passes may query the latency of a bundled instruction.
if (MI->isBundle()) {
unsigned Latency = 0;
MachineBasicBlock::const_instr_iterator I = MI->getIterator();
MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end();
while (++I != E && I->isInsideBundle()) {
if (I->getOpcode() != ARM::t2IT)
Latency += getInstrLatency(ItinData, &*I, PredCost);
}
return Latency;
}
const MCInstrDesc &MCID = MI->getDesc();
if (PredCost && (MCID.isCall() || MCID.hasImplicitDefOfPhysReg(ARM::CPSR))) {
// When predicated, CPSR is an additional source operand for CPSR updating
// instructions, this apparently increases their latencies.
*PredCost = 1;
}
// Be sure to call getStageLatency for an empty itinerary in case it has a
// valid MinLatency property.
if (!ItinData)
return MI->mayLoad() ? 3 : 1;
unsigned Class = MCID.getSchedClass();
// For instructions with variable uops, use uops as latency.
if (!ItinData->isEmpty() && ItinData->getNumMicroOps(Class) < 0)
return getNumMicroOps(ItinData, MI);
// For the common case, fall back on the itinerary's latency.
unsigned Latency = ItinData->getStageLatency(Class);
// Adjust for dynamic def-side opcode variants not captured by the itinerary.
unsigned DefAlign = MI->hasOneMemOperand()
? (*MI->memoperands_begin())->getAlignment() : 0;
int Adj = adjustDefLatency(Subtarget, MI, &MCID, DefAlign);
if (Adj >= 0 || (int)Latency > -Adj) {
return Latency + Adj;
}
return Latency;
}
int ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
SDNode *Node) const {
if (!Node->isMachineOpcode())
return 1;
if (!ItinData || ItinData->isEmpty())
return 1;
unsigned Opcode = Node->getMachineOpcode();
switch (Opcode) {
default:
return ItinData->getStageLatency(get(Opcode).getSchedClass());
case ARM::VLDMQIA:
case ARM::VSTMQIA:
return 2;
}
}
bool ARMBaseInstrInfo::
hasHighOperandLatency(const TargetSchedModel &SchedModel,
const MachineRegisterInfo *MRI,
const MachineInstr *DefMI, unsigned DefIdx,
const MachineInstr *UseMI, unsigned UseIdx) const {
unsigned DDomain = DefMI->getDesc().TSFlags & ARMII::DomainMask;
unsigned UDomain = UseMI->getDesc().TSFlags & ARMII::DomainMask;
if (Subtarget.isCortexA8() &&
(DDomain == ARMII::DomainVFP || UDomain == ARMII::DomainVFP))
// CortexA8 VFP instructions are not pipelined.
return true;
// Hoist VFP / NEON instructions with 4 or higher latency.
unsigned Latency
= SchedModel.computeOperandLatency(DefMI, DefIdx, UseMI, UseIdx);
if (Latency <= 3)
return false;
return DDomain == ARMII::DomainVFP || DDomain == ARMII::DomainNEON ||
UDomain == ARMII::DomainVFP || UDomain == ARMII::DomainNEON;
}
bool ARMBaseInstrInfo::
hasLowDefLatency(const TargetSchedModel &SchedModel,
const MachineInstr *DefMI, unsigned DefIdx) const {
const InstrItineraryData *ItinData = SchedModel.getInstrItineraries();
if (!ItinData || ItinData->isEmpty())
return false;
unsigned DDomain = DefMI->getDesc().TSFlags & ARMII::DomainMask;
if (DDomain == ARMII::DomainGeneral) {
unsigned DefClass = DefMI->getDesc().getSchedClass();
int DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
return (DefCycle != -1 && DefCycle <= 2);
}
return false;
}
bool ARMBaseInstrInfo::verifyInstruction(const MachineInstr *MI,
StringRef &ErrInfo) const {
if (convertAddSubFlagsOpcode(MI->getOpcode())) {
ErrInfo = "Pseudo flag setting opcodes only exist in Selection DAG";
return false;
}
return true;
}
// LoadStackGuard has so far only been implemented for MachO. Different code
// sequence is needed for other targets.
void ARMBaseInstrInfo::expandLoadStackGuardBase(MachineBasicBlock::iterator MI,
unsigned LoadImmOpc,
unsigned LoadOpc,
Reloc::Model RM) const {
MachineBasicBlock &MBB = *MI->getParent();
DebugLoc DL = MI->getDebugLoc();
unsigned Reg = MI->getOperand(0).getReg();
const GlobalValue *GV =
cast<GlobalValue>((*MI->memoperands_begin())->getValue());
MachineInstrBuilder MIB;
BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
.addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
if (Subtarget.GVIsIndirectSymbol(GV, RM)) {
MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
MIB.addReg(Reg, RegState::Kill).addImm(0);
unsigned Flag = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
MachinePointerInfo::getGOT(*MBB.getParent()), Flag, 4, 4);
MIB.addMemOperand(MMO);
AddDefaultPred(MIB);
}
MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
MIB.addReg(Reg, RegState::Kill).addImm(0);
MIB.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
AddDefaultPred(MIB);
}
bool
ARMBaseInstrInfo::isFpMLxInstruction(unsigned Opcode, unsigned &MulOpc,
unsigned &AddSubOpc,
bool &NegAcc, bool &HasLane) const {
DenseMap<unsigned, unsigned>::const_iterator I = MLxEntryMap.find(Opcode);
if (I == MLxEntryMap.end())
return false;
const ARM_MLxEntry &Entry = ARM_MLxTable[I->second];
MulOpc = Entry.MulOpc;
AddSubOpc = Entry.AddSubOpc;
NegAcc = Entry.NegAcc;
HasLane = Entry.HasLane;
return true;
}
//===----------------------------------------------------------------------===//
// Execution domains.
//===----------------------------------------------------------------------===//
//
// Some instructions go down the NEON pipeline, some go down the VFP pipeline,
// and some can go down both. The vmov instructions go down the VFP pipeline,
// but they can be changed to vorr equivalents that are executed by the NEON
// pipeline.
//
// We use the following execution domain numbering:
//
enum ARMExeDomain {
ExeGeneric = 0,
ExeVFP = 1,
ExeNEON = 2
};
//
// Also see ARMInstrFormats.td and Domain* enums in ARMBaseInfo.h
//
std::pair<uint16_t, uint16_t>
ARMBaseInstrInfo::getExecutionDomain(const MachineInstr *MI) const {
// If we don't have access to NEON instructions then we won't be able
// to swizzle anything to the NEON domain. Check to make sure.
if (Subtarget.hasNEON()) {
// VMOVD, VMOVRS and VMOVSR are VFP instructions, but can be changed to NEON
// if they are not predicated.
if (MI->getOpcode() == ARM::VMOVD && !isPredicated(*MI))
return std::make_pair(ExeVFP, (1 << ExeVFP) | (1 << ExeNEON));
// CortexA9 is particularly picky about mixing the two and wants these
// converted.
if (Subtarget.isCortexA9() && !isPredicated(*MI) &&
(MI->getOpcode() == ARM::VMOVRS || MI->getOpcode() == ARM::VMOVSR ||
MI->getOpcode() == ARM::VMOVS))
return std::make_pair(ExeVFP, (1 << ExeVFP) | (1 << ExeNEON));
}
// No other instructions can be swizzled, so just determine their domain.
unsigned Domain = MI->getDesc().TSFlags & ARMII::DomainMask;
if (Domain & ARMII::DomainNEON)
return std::make_pair(ExeNEON, 0);
// Certain instructions can go either way on Cortex-A8.
// Treat them as NEON instructions.
if ((Domain & ARMII::DomainNEONA8) && Subtarget.isCortexA8())
return std::make_pair(ExeNEON, 0);
if (Domain & ARMII::DomainVFP)
return std::make_pair(ExeVFP, 0);
return std::make_pair(ExeGeneric, 0);
}
static unsigned getCorrespondingDRegAndLane(const TargetRegisterInfo *TRI,
unsigned SReg, unsigned &Lane) {
unsigned DReg = TRI->getMatchingSuperReg(SReg, ARM::ssub_0, &ARM::DPRRegClass);
Lane = 0;
if (DReg != ARM::NoRegister)
return DReg;
Lane = 1;
DReg = TRI->getMatchingSuperReg(SReg, ARM::ssub_1, &ARM::DPRRegClass);
assert(DReg && "S-register with no D super-register?");
return DReg;
}
/// getImplicitSPRUseForDPRUse - Given a use of a DPR register and lane,
/// set ImplicitSReg to a register number that must be marked as implicit-use or
/// zero if no register needs to be defined as implicit-use.
///
/// If the function cannot determine if an SPR should be marked implicit use or
/// not, it returns false.
///
/// This function handles cases where an instruction is being modified from taking
/// an SPR to a DPR[Lane]. A use of the DPR is being added, which may conflict
/// with an earlier def of an SPR corresponding to DPR[Lane^1] (i.e. the other
/// lane of the DPR).
///
/// If the other SPR is defined, an implicit-use of it should be added. Else,
/// (including the case where the DPR itself is defined), it should not.
///
static bool getImplicitSPRUseForDPRUse(const TargetRegisterInfo *TRI,
MachineInstr *MI,
unsigned DReg, unsigned Lane,
unsigned &ImplicitSReg) {
// If the DPR is defined or used already, the other SPR lane will be chained
// correctly, so there is nothing to be done.
if (MI->definesRegister(DReg, TRI) || MI->readsRegister(DReg, TRI)) {
ImplicitSReg = 0;
return true;
}
// Otherwise we need to go searching to see if the SPR is set explicitly.
ImplicitSReg = TRI->getSubReg(DReg,
(Lane & 1) ? ARM::ssub_0 : ARM::ssub_1);
MachineBasicBlock::LivenessQueryResult LQR =
MI->getParent()->computeRegisterLiveness(TRI, ImplicitSReg, MI);
if (LQR == MachineBasicBlock::LQR_Live)
return true;
else if (LQR == MachineBasicBlock::LQR_Unknown)
return false;
// If the register is known not to be live, there is no need to add an
// implicit-use.
ImplicitSReg = 0;
return true;
}
void
ARMBaseInstrInfo::setExecutionDomain(MachineInstr *MI, unsigned Domain) const {
unsigned DstReg, SrcReg, DReg;
unsigned Lane;
MachineInstrBuilder MIB(*MI->getParent()->getParent(), MI);
const TargetRegisterInfo *TRI = &getRegisterInfo();
switch (MI->getOpcode()) {
default:
llvm_unreachable("cannot handle opcode!");
break;
case ARM::VMOVD:
if (Domain != ExeNEON)
break;
// Zap the predicate operands.
assert(!isPredicated(*MI) && "Cannot predicate a VORRd");
// Make sure we've got NEON instructions.
assert(Subtarget.hasNEON() && "VORRd requires NEON");
// Source instruction is %DDst = VMOVD %DSrc, 14, %noreg (; implicits)
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(1).getReg();
for (unsigned i = MI->getDesc().getNumOperands(); i; --i)
MI->RemoveOperand(i-1);
// Change to a %DDst = VORRd %DSrc, %DSrc, 14, %noreg (; implicits)
MI->setDesc(get(ARM::VORRd));
AddDefaultPred(MIB.addReg(DstReg, RegState::Define)
.addReg(SrcReg)
.addReg(SrcReg));
break;
case ARM::VMOVRS:
if (Domain != ExeNEON)
break;
assert(!isPredicated(*MI) && "Cannot predicate a VGETLN");
// Source instruction is %RDst = VMOVRS %SSrc, 14, %noreg (; implicits)
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(1).getReg();
for (unsigned i = MI->getDesc().getNumOperands(); i; --i)
MI->RemoveOperand(i-1);
DReg = getCorrespondingDRegAndLane(TRI, SrcReg, Lane);
// Convert to %RDst = VGETLNi32 %DSrc, Lane, 14, %noreg (; imps)
// Note that DSrc has been widened and the other lane may be undef, which
// contaminates the entire register.
MI->setDesc(get(ARM::VGETLNi32));
AddDefaultPred(MIB.addReg(DstReg, RegState::Define)
.addReg(DReg, RegState::Undef)
.addImm(Lane));
// The old source should be an implicit use, otherwise we might think it
// was dead before here.
MIB.addReg(SrcReg, RegState::Implicit);
break;
case ARM::VMOVSR: {
if (Domain != ExeNEON)
break;
assert(!isPredicated(*MI) && "Cannot predicate a VSETLN");
// Source instruction is %SDst = VMOVSR %RSrc, 14, %noreg (; implicits)
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(1).getReg();
DReg = getCorrespondingDRegAndLane(TRI, DstReg, Lane);
unsigned ImplicitSReg;
if (!getImplicitSPRUseForDPRUse(TRI, MI, DReg, Lane, ImplicitSReg))
break;
for (unsigned i = MI->getDesc().getNumOperands(); i; --i)
MI->RemoveOperand(i-1);
// Convert to %DDst = VSETLNi32 %DDst, %RSrc, Lane, 14, %noreg (; imps)
// Again DDst may be undefined at the beginning of this instruction.
MI->setDesc(get(ARM::VSETLNi32));
MIB.addReg(DReg, RegState::Define)
.addReg(DReg, getUndefRegState(!MI->readsRegister(DReg, TRI)))
.addReg(SrcReg)
.addImm(Lane);
AddDefaultPred(MIB);
// The narrower destination must be marked as set to keep previous chains
// in place.
MIB.addReg(DstReg, RegState::Define | RegState::Implicit);
if (ImplicitSReg != 0)
MIB.addReg(ImplicitSReg, RegState::Implicit);
break;
}
case ARM::VMOVS: {
if (Domain != ExeNEON)
break;
// Source instruction is %SDst = VMOVS %SSrc, 14, %noreg (; implicits)
DstReg = MI->getOperand(0).getReg();
SrcReg = MI->getOperand(1).getReg();
unsigned DstLane = 0, SrcLane = 0, DDst, DSrc;
DDst = getCorrespondingDRegAndLane(TRI, DstReg, DstLane);
DSrc = getCorrespondingDRegAndLane(TRI, SrcReg, SrcLane);
unsigned ImplicitSReg;
if (!getImplicitSPRUseForDPRUse(TRI, MI, DSrc, SrcLane, ImplicitSReg))
break;
for (unsigned i = MI->getDesc().getNumOperands(); i; --i)
MI->RemoveOperand(i-1);
if (DSrc == DDst) {
// Destination can be:
// %DDst = VDUPLN32d %DDst, Lane, 14, %noreg (; implicits)
MI->setDesc(get(ARM::VDUPLN32d));
MIB.addReg(DDst, RegState::Define)
.addReg(DDst, getUndefRegState(!MI->readsRegister(DDst, TRI)))
.addImm(SrcLane);
AddDefaultPred(MIB);
// Neither the source or the destination are naturally represented any
// more, so add them in manually.
MIB.addReg(DstReg, RegState::Implicit | RegState::Define);
MIB.addReg(SrcReg, RegState::Implicit);
if (ImplicitSReg != 0)
MIB.addReg(ImplicitSReg, RegState::Implicit);
break;
}
// In general there's no single instruction that can perform an S <-> S
// move in NEON space, but a pair of VEXT instructions *can* do the
// job. It turns out that the VEXTs needed will only use DSrc once, with
// the position based purely on the combination of lane-0 and lane-1
// involved. For example
// vmov s0, s2 -> vext.32 d0, d0, d1, #1 vext.32 d0, d0, d0, #1
// vmov s1, s3 -> vext.32 d0, d1, d0, #1 vext.32 d0, d0, d0, #1
// vmov s0, s3 -> vext.32 d0, d0, d0, #1 vext.32 d0, d1, d0, #1
// vmov s1, s2 -> vext.32 d0, d0, d0, #1 vext.32 d0, d0, d1, #1
//
// Pattern of the MachineInstrs is:
// %DDst = VEXTd32 %DSrc1, %DSrc2, Lane, 14, %noreg (;implicits)
MachineInstrBuilder NewMIB;
NewMIB = BuildMI(*MI->getParent(), MI, MI->getDebugLoc(),
get(ARM::VEXTd32), DDst);
// On the first instruction, both DSrc and DDst may be <undef> if present.
// Specifically when the original instruction didn't have them as an
// <imp-use>.
unsigned CurReg = SrcLane == 1 && DstLane == 1 ? DSrc : DDst;
bool CurUndef = !MI->readsRegister(CurReg, TRI);
NewMIB.addReg(CurReg, getUndefRegState(CurUndef));
CurReg = SrcLane == 0 && DstLane == 0 ? DSrc : DDst;
CurUndef = !MI->readsRegister(CurReg, TRI);
NewMIB.addReg(CurReg, getUndefRegState(CurUndef));
NewMIB.addImm(1);
AddDefaultPred(NewMIB);
if (SrcLane == DstLane)
NewMIB.addReg(SrcReg, RegState::Implicit);
MI->setDesc(get(ARM::VEXTd32));
MIB.addReg(DDst, RegState::Define);
// On the second instruction, DDst has definitely been defined above, so
// it is not <undef>. DSrc, if present, can be <undef> as above.
CurReg = SrcLane == 1 && DstLane == 0 ? DSrc : DDst;
CurUndef = CurReg == DSrc && !MI->readsRegister(CurReg, TRI);
MIB.addReg(CurReg, getUndefRegState(CurUndef));
CurReg = SrcLane == 0 && DstLane == 1 ? DSrc : DDst;
CurUndef = CurReg == DSrc && !MI->readsRegister(CurReg, TRI);
MIB.addReg(CurReg, getUndefRegState(CurUndef));
MIB.addImm(1);
AddDefaultPred(MIB);
if (SrcLane != DstLane)
MIB.addReg(SrcReg, RegState::Implicit);
// As before, the original destination is no longer represented, add it
// implicitly.
MIB.addReg(DstReg, RegState::Define | RegState::Implicit);
if (ImplicitSReg != 0)
MIB.addReg(ImplicitSReg, RegState::Implicit);
break;
}
}
}
//===----------------------------------------------------------------------===//
// Partial register updates
//===----------------------------------------------------------------------===//
//
// Swift renames NEON registers with 64-bit granularity. That means any
// instruction writing an S-reg implicitly reads the containing D-reg. The
// problem is mostly avoided by translating f32 operations to v2f32 operations
// on D-registers, but f32 loads are still a problem.
//
// These instructions can load an f32 into a NEON register:
//
// VLDRS - Only writes S, partial D update.
// VLD1LNd32 - Writes all D-regs, explicit partial D update, 2 uops.
// VLD1DUPd32 - Writes all D-regs, no partial reg update, 2 uops.
//
// FCONSTD can be used as a dependency-breaking instruction.
unsigned ARMBaseInstrInfo::
getPartialRegUpdateClearance(const MachineInstr *MI,
unsigned OpNum,
const TargetRegisterInfo *TRI) const {
if (!SwiftPartialUpdateClearance ||
!(Subtarget.isSwift() || Subtarget.isCortexA15()))
return 0;
assert(TRI && "Need TRI instance");
const MachineOperand &MO = MI->getOperand(OpNum);
if (MO.readsReg())
return 0;
unsigned Reg = MO.getReg();
int UseOp = -1;
switch(MI->getOpcode()) {
// Normal instructions writing only an S-register.
case ARM::VLDRS:
case ARM::FCONSTS:
case ARM::VMOVSR:
case ARM::VMOVv8i8:
case ARM::VMOVv4i16:
case ARM::VMOVv2i32:
case ARM::VMOVv2f32:
case ARM::VMOVv1i64:
UseOp = MI->findRegisterUseOperandIdx(Reg, false, TRI);
break;
// Explicitly reads the dependency.
case ARM::VLD1LNd32:
UseOp = 3;
break;
default:
return 0;
}
// If this instruction actually reads a value from Reg, there is no unwanted
// dependency.
if (UseOp != -1 && MI->getOperand(UseOp).readsReg())
return 0;
// We must be able to clobber the whole D-reg.
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
// Virtual register must be a foo:ssub_0<def,undef> operand.
if (!MO.getSubReg() || MI->readsVirtualRegister(Reg))
return 0;
} else if (ARM::SPRRegClass.contains(Reg)) {
// Physical register: MI must define the full D-reg.
unsigned DReg = TRI->getMatchingSuperReg(Reg, ARM::ssub_0,
&ARM::DPRRegClass);
if (!DReg || !MI->definesRegister(DReg, TRI))
return 0;
}
// MI has an unwanted D-register dependency.
// Avoid defs in the previous N instructrions.
return SwiftPartialUpdateClearance;
}
// Break a partial register dependency after getPartialRegUpdateClearance
// returned non-zero.
void ARMBaseInstrInfo::
breakPartialRegDependency(MachineBasicBlock::iterator MI,
unsigned OpNum,
const TargetRegisterInfo *TRI) const {
assert(MI && OpNum < MI->getDesc().getNumDefs() && "OpNum is not a def");
assert(TRI && "Need TRI instance");
const MachineOperand &MO = MI->getOperand(OpNum);
unsigned Reg = MO.getReg();
assert(TargetRegisterInfo::isPhysicalRegister(Reg) &&
"Can't break virtual register dependencies.");
unsigned DReg = Reg;
// If MI defines an S-reg, find the corresponding D super-register.
if (ARM::SPRRegClass.contains(Reg)) {
DReg = ARM::D0 + (Reg - ARM::S0) / 2;
assert(TRI->isSuperRegister(Reg, DReg) && "Register enums broken");
}
assert(ARM::DPRRegClass.contains(DReg) && "Can only break D-reg deps");
assert(MI->definesRegister(DReg, TRI) && "MI doesn't clobber full D-reg");
// FIXME: In some cases, VLDRS can be changed to a VLD1DUPd32 which defines
// the full D-register by loading the same value to both lanes. The
// instruction is micro-coded with 2 uops, so don't do this until we can
// properly schedule micro-coded instructions. The dispatcher stalls cause
// too big regressions.
// Insert the dependency-breaking FCONSTD before MI.
// 96 is the encoding of 0.5, but the actual value doesn't matter here.
AddDefaultPred(BuildMI(*MI->getParent(), MI, MI->getDebugLoc(),
get(ARM::FCONSTD), DReg).addImm(96));
MI->addRegisterKilled(DReg, TRI, true);
}
bool ARMBaseInstrInfo::hasNOP() const {
return Subtarget.getFeatureBits()[ARM::HasV6KOps];
}
bool ARMBaseInstrInfo::isSwiftFastImmShift(const MachineInstr *MI) const {
if (MI->getNumOperands() < 4)
return true;
unsigned ShOpVal = MI->getOperand(3).getImm();
unsigned ShImm = ARM_AM::getSORegOffset(ShOpVal);
// Swift supports faster shifts for: lsl 2, lsl 1, and lsr 1.
if ((ShImm == 1 && ARM_AM::getSORegShOp(ShOpVal) == ARM_AM::lsr) ||
((ShImm == 1 || ShImm == 2) &&
ARM_AM::getSORegShOp(ShOpVal) == ARM_AM::lsl))
return true;
return false;
}
bool ARMBaseInstrInfo::getRegSequenceLikeInputs(
const MachineInstr &MI, unsigned DefIdx,
SmallVectorImpl<RegSubRegPairAndIdx> &InputRegs) const {
assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
assert(MI.isRegSequenceLike() && "Invalid kind of instruction");
switch (MI.getOpcode()) {
case ARM::VMOVDRR:
// dX = VMOVDRR rY, rZ
// is the same as:
// dX = REG_SEQUENCE rY, ssub_0, rZ, ssub_1
// Populate the InputRegs accordingly.
// rY
const MachineOperand *MOReg = &MI.getOperand(1);
InputRegs.push_back(
RegSubRegPairAndIdx(MOReg->getReg(), MOReg->getSubReg(), ARM::ssub_0));
// rZ
MOReg = &MI.getOperand(2);
InputRegs.push_back(
RegSubRegPairAndIdx(MOReg->getReg(), MOReg->getSubReg(), ARM::ssub_1));
return true;
}
llvm_unreachable("Target dependent opcode missing");
}
bool ARMBaseInstrInfo::getExtractSubregLikeInputs(
const MachineInstr &MI, unsigned DefIdx,
RegSubRegPairAndIdx &InputReg) const {
assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
assert(MI.isExtractSubregLike() && "Invalid kind of instruction");
switch (MI.getOpcode()) {
case ARM::VMOVRRD:
// rX, rY = VMOVRRD dZ
// is the same as:
// rX = EXTRACT_SUBREG dZ, ssub_0
// rY = EXTRACT_SUBREG dZ, ssub_1
const MachineOperand &MOReg = MI.getOperand(2);
InputReg.Reg = MOReg.getReg();
InputReg.SubReg = MOReg.getSubReg();
InputReg.SubIdx = DefIdx == 0 ? ARM::ssub_0 : ARM::ssub_1;
return true;
}
llvm_unreachable("Target dependent opcode missing");
}
bool ARMBaseInstrInfo::getInsertSubregLikeInputs(
const MachineInstr &MI, unsigned DefIdx, RegSubRegPair &BaseReg,
RegSubRegPairAndIdx &InsertedReg) const {
assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
assert(MI.isInsertSubregLike() && "Invalid kind of instruction");
switch (MI.getOpcode()) {
case ARM::VSETLNi32:
// dX = VSETLNi32 dY, rZ, imm
const MachineOperand &MOBaseReg = MI.getOperand(1);
const MachineOperand &MOInsertedReg = MI.getOperand(2);
const MachineOperand &MOIndex = MI.getOperand(3);
BaseReg.Reg = MOBaseReg.getReg();
BaseReg.SubReg = MOBaseReg.getSubReg();
InsertedReg.Reg = MOInsertedReg.getReg();
InsertedReg.SubReg = MOInsertedReg.getSubReg();
InsertedReg.SubIdx = MOIndex.getImm() == 0 ? ARM::ssub_0 : ARM::ssub_1;
return true;
}
llvm_unreachable("Target dependent opcode missing");
}
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