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llvm/llvm-project/6b26457a0ef2994de54606eb5c356cb897cadda2/./llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
blob: 42b8977e3aceab82ff7d4610467dcdcbc508e134 [file]
//===-- ARMBaseInstrInfo.cpp - ARM Instruction Information ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the Base ARM implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARMBaseInstrInfo.h"
#include "ARMBaseRegisterInfo.h"
#include "ARMConstantPoolValue.h"
#include "ARMFeatures.h"
#include "ARMHazardRecognizer.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "MCTargetDesc/ARMBaseInfo.h"
#include "MVETailPredUtils.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/CFIInstBuilder.h"
#include "llvm/CodeGen/DFAPacketizer.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachinePipeliner.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineScheduler.h"
#include "llvm/CodeGen/MultiHazardRecognizer.h"
#include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSchedule.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <new>
#include <utility>
#include <vector>
using namespace llvm;
#define DEBUG_TYPE "arm-instrinfo"
#define GET_INSTRINFO_CTOR_DTOR
#include "ARMGenInstrInfo.inc"
/// 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,
const ARMBaseRegisterInfo &TRI)
: ARMGenInstrInfo(STI, TRI, ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
Subtarget(STI) {
for (unsigned i = 0, e = std::size(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);
}
// Called during:
// - pre-RA scheduling
// - post-RA scheduling when FeatureUseMISched is set
ScheduleHazardRecognizer *ARMBaseInstrInfo::CreateTargetMIHazardRecognizer(
const InstrItineraryData *II, const ScheduleDAGMI *DAG) const {
MultiHazardRecognizer *MHR = new MultiHazardRecognizer();
// We would like to restrict this hazard recognizer to only
// post-RA scheduling; we can tell that we're post-RA because we don't
// track VRegLiveness.
// Cortex-M7: TRM indicates that there is a single ITCM bank and two DTCM
// banks banked on bit 2. Assume that TCMs are in use.
if (Subtarget.isCortexM7() && !DAG->hasVRegLiveness())
MHR->AddHazardRecognizer(
std::make_unique<ARMBankConflictHazardRecognizer>(DAG, 0x4, true));
// Not inserting ARMHazardRecognizerFPMLx because that would change
// legacy behavior
auto BHR = TargetInstrInfo::CreateTargetMIHazardRecognizer(II, DAG);
MHR->AddHazardRecognizer(std::unique_ptr<ScheduleHazardRecognizer>(BHR));
return MHR;
}
// Called during post-RA scheduling when FeatureUseMISched is not set
ScheduleHazardRecognizer *ARMBaseInstrInfo::
CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
const ScheduleDAG *DAG) const {
MultiHazardRecognizer *MHR = new MultiHazardRecognizer();
if (Subtarget.isThumb2() || Subtarget.hasVFP2Base())
MHR->AddHazardRecognizer(std::make_unique<ARMHazardRecognizerFPMLx>());
auto BHR = TargetInstrInfo::CreateTargetPostRAHazardRecognizer(II, DAG);
if (BHR)
MHR->AddHazardRecognizer(std::unique_ptr<ScheduleHazardRecognizer>(BHR));
return MHR;
}
// Branch analysis.
// Cond vector output format:
// 0 elements indicates an unconditional branch
// 2 elements indicates a conditional branch; the elements are
// the condition to check and the CPSR.
// 3 elements indicates a hardware loop end; the elements
// are the opcode, the operand value to test, and a dummy
// operand used to pad out to 3 operands.
bool ARMBaseInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
TBB = nullptr;
FBB = nullptr;
MachineBasicBlock::instr_iterator I = MBB.instr_end();
if (I == MBB.instr_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, predicated nonterminators and speculation
// barrier terminators.
while (I->isDebugInstr() || !I->isTerminator() ||
isSpeculationBarrierEndBBOpcode(I->getOpcode()) ||
I->getOpcode() == ARM::t2DoLoopStartTP){
if (I == MBB.instr_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 = true;
} else if (I->getOpcode() == ARM::t2LoopEnd &&
MBB.getParent()
->getSubtarget<ARMSubtarget>()
.enableMachinePipeliner()) {
if (!Cond.empty())
return true;
FBB = TBB;
TBB = I->getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(I->getOpcode()));
Cond.push_back(I->getOperand(0));
Cond.push_back(MachineOperand::CreateImm(0));
} 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.instr_end()) {
MachineInstr &InstToDelete = *DI;
++DI;
// Speculation barriers must not be deleted.
if (isSpeculationBarrierEndBBOpcode(InstToDelete.getOpcode()))
continue;
InstToDelete.eraseFromParent();
}
}
}
if (CantAnalyze) {
// We may not be able to analyze the block, but we could still have
// an unconditional branch as the last instruction in the block, which
// just branches to layout successor. If this is the case, then just
// remove it if we're allowed to make modifications.
if (AllowModify && !isPredicated(MBB.back()) &&
isUncondBranchOpcode(MBB.back().getOpcode()) &&
TBB && MBB.isLayoutSuccessor(TBB))
removeBranch(MBB);
return true;
}
if (I == MBB.instr_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,
int *BytesRemoved) const {
assert(!BytesRemoved && "code size not handled");
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return 0;
if (!isUncondBranchOpcode(I->getOpcode()) &&
!isCondBranchOpcode(I->getOpcode()) && I->getOpcode() != ARM::t2LoopEnd)
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (!isCondBranchOpcode(I->getOpcode()) && I->getOpcode() != ARM::t2LoopEnd)
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned ARMBaseInstrInfo::insertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
const DebugLoc &DL,
int *BytesAdded) const {
assert(!BytesAdded && "code size not handled");
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 || Cond.size() == 3) &&
"ARM branch conditions have two or three 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).add(predOps(ARMCC::AL));
else
BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB);
} else if (Cond.size() == 2) {
BuildMI(&MBB, DL, get(BccOpc))
.addMBB(TBB)
.addImm(Cond[0].getImm())
.add(Cond[1]);
} else
BuildMI(&MBB, DL, get(Cond[0].getImm())).add(Cond[1]).addMBB(TBB);
return 1;
}
// Two-way conditional branch.
if (Cond.size() == 2)
BuildMI(&MBB, DL, get(BccOpc))
.addMBB(TBB)
.addImm(Cond[0].getImm())
.add(Cond[1]);
else if (Cond.size() == 3)
BuildMI(&MBB, DL, get(Cond[0].getImm())).add(Cond[1]).addMBB(TBB);
if (isThumb)
BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB).add(predOps(ARMCC::AL));
else
BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB);
return 2;
}
bool ARMBaseInstrInfo::
reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
if (Cond.size() == 2) {
ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
Cond[0].setImm(ARMCC::getOppositeCondition(CC));
return false;
}
return true;
}
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;
}
std::string ARMBaseInstrInfo::createMIROperandComment(
const MachineInstr &MI, const MachineOperand &Op, unsigned OpIdx,
const TargetRegisterInfo *TRI) const {
// First, let's see if there is a generic comment for this operand
std::string GenericComment =
TargetInstrInfo::createMIROperandComment(MI, Op, OpIdx, TRI);
if (!GenericComment.empty())
return GenericComment;
// If not, check if we have an immediate operand.
if (!Op.isImm())
return std::string();
// And print its corresponding condition code if the immediate is a
// predicate.
int FirstPredOp = MI.findFirstPredOperandIdx();
if (FirstPredOp != (int) OpIdx)
return std::string();
std::string CC = "CC::";
CC += ARMCondCodeToString((ARMCC::CondCodes)Op.getImm());
return CC;
}
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());
// Thumb 1 arithmetic instructions do not set CPSR when executed inside an
// IT block. This affects how they are printed.
const MCInstrDesc &MCID = MI.getDesc();
if (MCID.TSFlags & ARMII::ThumbArithFlagSetting) {
assert(MCID.operands()[1].isOptionalDef() &&
"CPSR def isn't expected operand");
assert((MI.getOperand(1).isDead() ||
MI.getOperand(1).getReg() != ARM::CPSR) &&
"if conversion tried to stop defining used CPSR");
MI.getOperand(1).setReg(Register());
}
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::ClobbersPredicate(MachineInstr &MI,
std::vector<MachineOperand> &Pred,
bool SkipDead) const {
bool Found = false;
for (const MachineOperand &MO : MI.operands()) {
bool ClobbersCPSR = MO.isRegMask() && MO.clobbersPhysReg(ARM::CPSR);
bool IsCPSR = MO.isReg() && MO.isDef() && MO.getReg() == ARM::CPSR;
if (ClobbersCPSR || IsCPSR) {
// Filter out T1 instructions that have a dead CPSR,
// allowing IT blocks to be generated containing T1 instructions
const MCInstrDesc &MCID = MI.getDesc();
if (MCID.TSFlags & ARMII::ThumbArithFlagSetting && MO.isDead() &&
SkipDead)
continue;
Pred.push_back(MO);
Found = true;
}
}
return Found;
}
bool ARMBaseInstrInfo::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 !ARMBaseInstrInfo::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(const MachineInstr &MI) const {
if (!MI.isPredicable())
return false;
if (MI.isBundle())
return false;
if (!isEligibleForITBlock(&MI))
return false;
const MachineFunction *MF = MI.getParent()->getParent();
const ARMFunctionInfo *AFI =
MF->getInfo<ARMFunctionInfo>();
// Neon instructions in Thumb2 IT blocks are deprecated, see ARMARM.
// In their ARM encoding, they can't be encoded in a conditional form.
if ((MI.getDesc().TSFlags & ARMII::DomainMask) == ARMII::DomainNEON)
return false;
// Make indirect control flow changes unpredictable when SLS mitigation is
// enabled.
const ARMSubtarget &ST = MF->getSubtarget<ARMSubtarget>();
if (ST.hardenSlsRetBr() && isIndirectControlFlowNotComingBack(MI))
return false;
if (ST.hardenSlsBlr() && isIndirectCall(MI))
return false;
if (AFI->isThumb2Function()) {
if (getSubtarget().restrictIT())
return isV8EligibleForIT(&MI);
}
return true;
}
namespace llvm {
template <> bool IsCPSRDead<MachineInstr>(const MachineInstr *MI) {
for (const MachineOperand &MO : MI->operands()) {
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;
}
} // end namespace llvm
/// 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();
switch (MI.getOpcode()) {
default:
// Return the size specified in .td file. If there's none, return 0, as we
// can't define a default size (Thumb1 instructions are 2 bytes, Thumb2
// instructions are 2-4 bytes, and ARM instructions are 4 bytes), in
// contrast to AArch64 instructions which have a default size of 4 bytes for
// example.
return MCID.getSize();
case TargetOpcode::BUNDLE:
return getInstBundleSize(MI);
case TargetOpcode::COPY:
if (!MF->getInfo<ARMFunctionInfo>()->isThumbFunction())
return 4;
else
return 2;
case TargetOpcode::PATCHABLE_FUNCTION_ENTER:
case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
case TargetOpcode::PATCHABLE_TAIL_CALL:
// Size of xray sled: Branch + 6 nops.
return 28;
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::SPACE:
return MI.getOperand(1).getImm();
case ARM::INLINEASM:
case ARM::INLINEASM_BR: {
// If this machine instr is an inline asm, measure it.
unsigned Size = getInlineAsmLength(MI.getOperand(0).getSymbolName(), MAI);
if (!MF->getInfo<ARMFunctionInfo>()->isThumbFunction())
Size = alignTo(Size, 4);
return Size;
}
case ARM::Int_eh_sjlj_longjmp:
return Subtarget.isTargetDarwin() || Subtarget.isTargetWindows() ? 16 : 20;
case ARM::tInt_eh_sjlj_longjmp:
return Subtarget.isTargetDarwin() || Subtarget.isTargetWindows() ? 10 : 12;
}
}
void ARMBaseInstrInfo::copyFromCPSR(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
MCRegister 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);
MIB.add(predOps(ARMCC::AL))
.addReg(ARM::CPSR, RegState::Implicit | getKillRegState(KillSrc));
}
void ARMBaseInstrInfo::copyToCPSR(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
MCRegister 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))
.add(predOps(ARMCC::AL))
.addReg(ARM::CPSR, RegState::Implicit | RegState::Define);
}
void llvm::addUnpredicatedMveVpredNOp(MachineInstrBuilder &MIB) {
MIB.addImm(ARMVCC::None);
MIB.addReg(0);
MIB.addReg(0); // tp_reg
}
void llvm::addUnpredicatedMveVpredROp(MachineInstrBuilder &MIB,
Register DestReg) {
addUnpredicatedMveVpredNOp(MIB);
MIB.addReg(DestReg, RegState::Undef);
}
void llvm::addPredicatedMveVpredNOp(MachineInstrBuilder &MIB, unsigned Cond) {
MIB.addImm(Cond);
MIB.addReg(ARM::VPR, RegState::Implicit);
MIB.addReg(0); // tp_reg
}
void llvm::addPredicatedMveVpredROp(MachineInstrBuilder &MIB,
unsigned Cond, unsigned Inactive) {
addPredicatedMveVpredNOp(MIB, Cond);
MIB.addReg(Inactive);
}
void ARMBaseInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, Register DestReg,
Register SrcReg, bool KillSrc,
bool RenamableDest,
bool RenamableSrc) const {
bool GPRDest = ARM::GPRRegClass.contains(DestReg);
bool GPRSrc = ARM::GPRRegClass.contains(SrcReg);
if (GPRDest && GPRSrc) {
BuildMI(MBB, I, DL, get(ARM::MOVr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.add(predOps(ARMCC::AL))
.add(condCodeOp());
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.hasFP64())
Opc = ARM::VMOVD;
else if (ARM::QPRRegClass.contains(DestReg, SrcReg))
Opc = Subtarget.hasNEON() ? ARM::VORRq : ARM::MQPRCopy;
if (Opc) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc), DestReg);
MIB.addReg(SrcReg, getKillRegState(KillSrc));
if (Opc == ARM::VORRq || Opc == ARM::MVE_VORR)
MIB.addReg(SrcReg, getKillRegState(KillSrc));
if (Opc == ARM::MVE_VORR)
addUnpredicatedMveVpredROp(MIB, DestReg);
else if (Opc != ARM::MQPRCopy)
MIB.add(predOps(ARMCC::AL));
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 = Subtarget.hasNEON() ? ARM::VORRq : ARM::MVE_VORR;
BeginIdx = ARM::qsub_0;
SubRegs = 2;
} else if (ARM::QQQQPRRegClass.contains(DestReg, SrcReg)) {
Opc = Subtarget.hasNEON() ? ARM::VORRq : ARM::MVE_VORR;
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.hasFP64()) {
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;
} else if (DestReg == ARM::VPR) {
assert(ARM::GPRRegClass.contains(SrcReg));
BuildMI(MBB, I, I->getDebugLoc(), get(ARM::VMSR_P0), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.add(predOps(ARMCC::AL));
return;
} else if (SrcReg == ARM::VPR) {
assert(ARM::GPRRegClass.contains(DestReg));
BuildMI(MBB, I, I->getDebugLoc(), get(ARM::VMRS_P0), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.add(predOps(ARMCC::AL));
return;
} else if (DestReg == ARM::FPSCR_NZCV) {
assert(ARM::GPRRegClass.contains(SrcReg));
BuildMI(MBB, I, I->getDebugLoc(), get(ARM::VMSR_FPSCR_NZCVQC), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.add(predOps(ARMCC::AL));
return;
} else if (SrcReg == ARM::FPSCR_NZCV) {
assert(ARM::GPRRegClass.contains(DestReg));
BuildMI(MBB, I, I->getDebugLoc(), get(ARM::VMRS_FPSCR_NZCVQC), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.add(predOps(ARMCC::AL));
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) {
Register Dst = TRI->getSubReg(DestReg, BeginIdx + i * Spacing);
Register 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 (NEON or MVE) takes two source operands.
if (Opc == ARM::VORRq || Opc == ARM::MVE_VORR) {
Mov.addReg(Src);
}
// MVE VORR takes predicate operands in place of an ordinary condition.
if (Opc == ARM::MVE_VORR)
addUnpredicatedMveVpredROp(Mov, Dst);
else
Mov = Mov.add(predOps(ARMCC::AL));
// MOVr can set CC.
if (Opc == ARM::MOVr)
Mov = Mov.add(condCodeOp());
}
// Add implicit super-register defs and kills to the last instruction.
Mov->addRegisterDefined(DestReg, TRI);
if (KillSrc)
Mov->addRegisterKilled(SrcReg, TRI);
}
std::optional<DestSourcePair>
ARMBaseInstrInfo::isCopyInstrImpl(const MachineInstr &MI) const {
// VMOVRRD is also a copy instruction but it requires
// special way of handling. It is more complex copy version
// and since that we are not considering it. For recognition
// of such instruction isExtractSubregLike MI interface function
// could be used.
// VORRq is considered as a move only if two inputs are
// the same register.
if (!MI.isMoveReg() ||
(MI.getOpcode() == ARM::VORRq &&
MI.getOperand(1).getReg() != MI.getOperand(2).getReg()))
return std::nullopt;
return DestSourcePair{MI.getOperand(0), MI.getOperand(1)};
}
std::optional<ParamLoadedValue>
ARMBaseInstrInfo::describeLoadedValue(const MachineInstr &MI,
Register Reg) const {
if (auto DstSrcPair = isCopyInstrImpl(MI)) {
Register DstReg = DstSrcPair->Destination->getReg();
// TODO: We don't handle cases where the forwarding reg is narrower/wider
// than the copy registers. Consider for example:
//
// s16 = VMOVS s0
// s17 = VMOVS s1
// call @callee(d0)
//
// We'd like to describe the call site value of d0 as d8, but this requires
// gathering and merging the descriptions for the two VMOVS instructions.
//
// We also don't handle the reverse situation, where the forwarding reg is
// narrower than the copy destination:
//
// d8 = VMOVD d0
// call @callee(s1)
//
// We need to produce a fragment description (the call site value of s1 is
// /not/ just d8).
if (DstReg != Reg)
return std::nullopt;
}
return TargetInstrInfo::describeLoadedValue(MI, Reg);
}
const MachineInstrBuilder &ARMBaseInstrInfo::AddDReg(MachineInstrBuilder &MIB,
unsigned Reg,
unsigned SubIdx,
RegState State) const {
if (!SubIdx)
return MIB.addReg(Reg, State);
if (Register::isPhysicalRegister(Reg))
return MIB.addReg(getRegisterInfo().getSubReg(Reg, SubIdx), State);
return MIB.addReg(Reg, State, SubIdx);
}
void ARMBaseInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Register SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC,
Register VReg,
MachineInstr::MIFlag Flags) const {
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = MF.getFrameInfo();
Align Alignment = MFI.getObjectAlign(FI);
const ARMBaseRegisterInfo &TRI = getRegisterInfo();
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
MFI.getObjectSize(FI), Alignment);
switch (TRI.getSpillSize(*RC)) {
case 2:
if (ARM::HPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTRH))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else
llvm_unreachable("Unknown reg class!");
break;
case 4:
if (ARM::GPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::STRi12))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTRS))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::VCCRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTR_P0_off))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::cl_FPSCR_NZCVRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTR_FPSCR_NZCVQC_off))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else
llvm_unreachable("Unknown reg class!");
break;
case 8:
if (ARM::DPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTRD))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
if (Subtarget.hasV5TEOps()) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DebugLoc(), get(ARM::STRD));
AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill));
AddDReg(MIB, SrcReg, ARM::gsub_1, {});
MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
// Fallback to STM instruction, which has existed since the dawn of
// time.
MachineInstrBuilder MIB = BuildMI(MBB, I, DebugLoc(), get(ARM::STMIA))
.addFrameIndex(FI)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill));
AddDReg(MIB, SrcReg, ARM::gsub_1, {});
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 16:
if (ARM::DPairRegClass.hasSubClassEq(RC) && Subtarget.hasNEON()) {
// Use aligned spills if the stack can be realigned.
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF)) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VST1q64))
.addFrameIndex(FI)
.addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
BuildMI(MBB, I, DebugLoc(), get(ARM::VSTMQIA))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
}
} else if (ARM::QPRRegClass.hasSubClassEq(RC) &&
Subtarget.hasMVEIntegerOps()) {
auto MIB = BuildMI(MBB, I, DebugLoc(), get(ARM::MVE_VSTRWU32));
MIB.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO);
addUnpredicatedMveVpredNOp(MIB);
} else
llvm_unreachable("Unknown reg class!");
break;
case 24:
if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
// Use aligned spills if the stack can be realigned.
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF) &&
Subtarget.hasNEON()) {
BuildMI(MBB, I, DebugLoc(), get(ARM::VST1d64TPseudo))
.addFrameIndex(FI)
.addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
MachineInstrBuilder MIB = BuildMI(MBB, I, DebugLoc(),
get(ARM::VSTMDIA))
.addFrameIndex(FI)
.add(predOps(ARMCC::AL))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill));
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, {});
AddDReg(MIB, SrcReg, ARM::dsub_2, {});
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 32:
if (ARM::QQPRRegClass.hasSubClassEq(RC) ||
ARM::MQQPRRegClass.hasSubClassEq(RC) ||
ARM::DQuadRegClass.hasSubClassEq(RC)) {
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF) &&
Subtarget.hasNEON()) {
// FIXME: It's possible to only store part of the QQ register if the
// spilled def has a sub-register index.
BuildMI(MBB, I, DebugLoc(), get(ARM::VST1d64QPseudo))
.addFrameIndex(FI)
.addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (Subtarget.hasMVEIntegerOps()) {
BuildMI(MBB, I, DebugLoc(), get(ARM::MQQPRStore))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addMemOperand(MMO);
} else {
MachineInstrBuilder MIB = BuildMI(MBB, I, DebugLoc(),
get(ARM::VSTMDIA))
.addFrameIndex(FI)
.add(predOps(ARMCC::AL))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill));
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, {});
AddDReg(MIB, SrcReg, ARM::dsub_3, {});
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 64:
if (ARM::MQQQQPRRegClass.hasSubClassEq(RC) &&
Subtarget.hasMVEIntegerOps()) {
BuildMI(MBB, I, DebugLoc(), get(ARM::MQQQQPRStore))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addMemOperand(MMO);
} else if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DebugLoc(), get(ARM::VSTMDIA))
.addFrameIndex(FI)
.add(predOps(ARMCC::AL))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill));
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_3, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_4, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_5, {});
MIB = AddDReg(MIB, SrcReg, ARM::dsub_6, {});
AddDReg(MIB, SrcReg, ARM::dsub_7, {});
} else
llvm_unreachable("Unknown reg class!");
break;
default:
llvm_unreachable("Unknown reg class!");
}
}
Register 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:
case ARM::VSTRH:
case ARM::VSTR_P0_off:
case ARM::VSTR_FPSCR_NZCVQC_off:
case ARM::MVE_VSTRWU32:
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;
case ARM::MQQPRStore:
case ARM::MQQQQPRStore:
if (MI.getOperand(1).isFI()) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
break;
}
return 0;
}
Register ARMBaseInstrInfo::isStoreToStackSlotPostFE(const MachineInstr &MI,
int &FrameIndex) const {
SmallVector<const MachineMemOperand *, 1> Accesses;
if (MI.mayStore() && hasStoreToStackSlot(MI, Accesses) &&
Accesses.size() == 1) {
FrameIndex =
cast<FixedStackPseudoSourceValue>(Accesses.front()->getPseudoValue())
->getFrameIndex();
return true;
}
return false;
}
void ARMBaseInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Register DestReg, int FI,
const TargetRegisterClass *RC,
Register VReg, unsigned SubReg,
MachineInstr::MIFlag Flags) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = MF.getFrameInfo();
const Align Alignment = MFI.getObjectAlign(FI);
MachineMemOperand *MMO = MF.getMachineMemOperand(
MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
MFI.getObjectSize(FI), Alignment);
const ARMBaseRegisterInfo &TRI = getRegisterInfo();
switch (TRI.getSpillSize(*RC)) {
case 2:
if (ARM::HPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::VLDRH), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else
llvm_unreachable("Unknown reg class!");
break;
case 4:
if (ARM::GPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::LDRi12), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::VLDRS), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::VCCRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::VLDR_P0_off), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (ARM::cl_FPSCR_NZCVRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::VLDR_FPSCR_NZCVQC_off), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else
llvm_unreachable("Unknown reg class!");
break;
case 8:
if (ARM::DPRRegClass.hasSubClassEq(RC)) {
BuildMI(MBB, I, DL, get(ARM::VLDRD), DestReg)
.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} 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);
AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead);
MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
// Fallback to LDM instruction, which has existed since the dawn of
// time.
MIB = BuildMI(MBB, I, DL, get(ARM::LDMIA))
.addFrameIndex(FI)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
MIB = AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead);
}
if (DestReg.isPhysical())
MIB.addReg(DestReg, RegState::ImplicitDefine);
} else
llvm_unreachable("Unknown reg class!");
break;
case 16:
if (ARM::DPairRegClass.hasSubClassEq(RC) && Subtarget.hasNEON()) {
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF)) {
BuildMI(MBB, I, DL, get(ARM::VLD1q64), DestReg)
.addFrameIndex(FI)
.addImm(16)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
BuildMI(MBB, I, DL, get(ARM::VLDMQIA), DestReg)
.addFrameIndex(FI)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
}
} else if (ARM::QPRRegClass.hasSubClassEq(RC) &&
Subtarget.hasMVEIntegerOps()) {
auto MIB = BuildMI(MBB, I, DL, get(ARM::MVE_VLDRWU32), DestReg);
MIB.addFrameIndex(FI)
.addImm(0)
.addMemOperand(MMO);
addUnpredicatedMveVpredNOp(MIB);
} else
llvm_unreachable("Unknown reg class!");
break;
case 24:
if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF) &&
Subtarget.hasNEON()) {
BuildMI(MBB, I, DL, get(ARM::VLD1d64TPseudo), DestReg)
.addFrameIndex(FI)
.addImm(16)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead);
if (DestReg.isPhysical())
MIB.addReg(DestReg, RegState::ImplicitDefine);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 32:
if (ARM::QQPRRegClass.hasSubClassEq(RC) ||
ARM::MQQPRRegClass.hasSubClassEq(RC) ||
ARM::DQuadRegClass.hasSubClassEq(RC)) {
if (Alignment >= 16 && getRegisterInfo().canRealignStack(MF) &&
Subtarget.hasNEON()) {
BuildMI(MBB, I, DL, get(ARM::VLD1d64QPseudo), DestReg)
.addFrameIndex(FI)
.addImm(16)
.addMemOperand(MMO)
.add(predOps(ARMCC::AL));
} else if (Subtarget.hasMVEIntegerOps()) {
BuildMI(MBB, I, DL, get(ARM::MQQPRLoad), DestReg)
.addFrameIndex(FI)
.addMemOperand(MMO);
} else {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI)
.add(predOps(ARMCC::AL))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead);
if (DestReg.isPhysical())
MIB.addReg(DestReg, RegState::ImplicitDefine);
}
} else
llvm_unreachable("Unknown reg class!");
break;
case 64:
if (ARM::MQQQQPRRegClass.hasSubClassEq(RC) &&
Subtarget.hasMVEIntegerOps()) {
BuildMI(MBB, I, DL, get(ARM::MQQQQPRLoad), DestReg)
.addFrameIndex(FI)
.addMemOperand(MMO);
} else if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
.addFrameIndex(FI)
.add(predOps(ARMCC::AL))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_4, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_5, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_6, RegState::DefineNoRead);
MIB = AddDReg(MIB, DestReg, ARM::dsub_7, RegState::DefineNoRead);
if (DestReg.isPhysical())
MIB.addReg(DestReg, RegState::ImplicitDefine);
} else
llvm_unreachable("Unknown reg class!");
break;
default:
llvm_unreachable("Unknown regclass!");
}
}
Register 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:
case ARM::VLDRH:
case ARM::VLDR_P0_off:
case ARM::VLDR_FPSCR_NZCVQC_off:
case ARM::MVE_VLDRWU32:
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::VLD1d8TPseudo:
case ARM::VLD1d16TPseudo:
case ARM::VLD1d32TPseudo:
case ARM::VLD1d64TPseudo:
case ARM::VLD1d8QPseudo:
case ARM::VLD1d16QPseudo:
case ARM::VLD1d32QPseudo:
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;
case ARM::MQQPRLoad:
case ARM::MQQQQPRLoad:
if (MI.getOperand(1).isFI()) {
FrameIndex = MI.getOperand(1).getIndex();
return MI.getOperand(0).getReg();
}
break;
}
return 0;
}
Register ARMBaseInstrInfo::isLoadFromStackSlotPostFE(const MachineInstr &MI,
int &FrameIndex) const {
SmallVector<const MachineMemOperand *, 1> Accesses;
if (MI.mayLoad() && hasLoadFromStackSlot(MI, Accesses) &&
Accesses.size() == 1) {
FrameIndex =
cast<FixedStackPseudoSourceValue>(Accesses.front()->getPseudoValue())
->getFrameIndex();
return true;
}
return false;
}
/// Expands MEMCPY to either LDMIA/STMIA or LDMIA_UPD/STMID_UPD
/// depending on whether the result is used.
void ARMBaseInstrInfo::expandMEMCPY(MachineBasicBlock::iterator MI) const {
bool isThumb1 = Subtarget.isThumb1Only();
bool isThumb2 = Subtarget.isThumb2();
const ARMBaseInstrInfo *TII = Subtarget.getInstrInfo();
DebugLoc dl = MI->getDebugLoc();
MachineBasicBlock *BB = MI->getParent();
MachineInstrBuilder LDM, STM;
if (isThumb1 || !MI->getOperand(1).isDead()) {
MachineOperand LDWb(MI->getOperand(1));
LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA_UPD
: isThumb1 ? ARM::tLDMIA_UPD
: ARM::LDMIA_UPD))
.add(LDWb);
} else {
LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA : ARM::LDMIA));
}
if (isThumb1 || !MI->getOperand(0).isDead()) {
MachineOperand STWb(MI->getOperand(0));
STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA_UPD
: isThumb1 ? ARM::tSTMIA_UPD
: ARM::STMIA_UPD))
.add(STWb);
} else {
STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA : ARM::STMIA));
}
MachineOperand LDBase(MI->getOperand(3));
LDM.add(LDBase).add(predOps(ARMCC::AL));
MachineOperand STBase(MI->getOperand(2));
STM.add(STBase).add(predOps(ARMCC::AL));
// Sort the scratch registers into ascending order.
const TargetRegisterInfo &TRI = getRegisterInfo();
SmallVector<unsigned, 6> ScratchRegs;
for (MachineOperand &MO : llvm::drop_begin(MI->operands(), 5))
ScratchRegs.push_back(MO.getReg());
llvm::sort(ScratchRegs,
[&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(MI);
}
bool ARMBaseInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
if (MI.getOpcode() == TargetOpcode::LOAD_STACK_GUARD) {
expandLoadStackGuard(MI);
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 (!MI.isCopy() || Subtarget.dontWidenVMOVS() || !Subtarget.hasFP64())
return false;
// Look for a copy between even S-registers. That is where we keep floats
// when using NEON v2f32 instructions for f32 arithmetic.
Register DstRegS = MI.getOperand(0).getReg();
Register SrcRegS = MI.getOperand(1).getReg();
if (!ARM::SPRRegClass.contains(DstRegS, SrcRegS))
return false;
const TargetRegisterInfo *TRI = &getRegisterInfo();
MCRegister DstRegD =
TRI->getMatchingSuperReg(DstRegS, ARM::ssub_0, &ARM::DPRRegClass);
MCRegister 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.
LLVM_DEBUG(dbgs() << "widening: " << MI);
MachineInstrBuilder MIB(*MI.getParent()->getParent(), MI);
// Get rid of the old implicit-def of DstRegD. Leave it if it defines a Q-reg
// or some other super-register.
int ImpDefIdx = MI.findRegisterDefOperandIdx(DstRegD, /*TRI=*/nullptr);
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);
MIB.add(predOps(ARMCC::AL));
// 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);
}
LLVM_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.getAlign());
return PCLabelId;
}
void ARMBaseInstrInfo::reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
Register DestReg, unsigned SubIdx,
const MachineInstr &Orig,
LaneBitmask UsedLanes) 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);
BuildMI(MBB, I, Orig.getDebugLoc(), get(Opcode), DestReg)
.addConstantPoolIndex(CPI)
.addImm(PCLabelId)
.cloneMemRefs(Orig);
break;
}
}
}
MachineInstr &
ARMBaseInstrInfo::duplicate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator InsertBefore,
const MachineInstr &Orig) const {
MachineInstr &Cloned = TargetInstrInfo::duplicate(MBB, InsertBefore, Orig);
MachineBasicBlock::instr_iterator I = Cloned.getIterator();
for (;;) {
switch (I->getOpcode()) {
case ARM::tLDRpci_pic:
case ARM::t2LDRpci_pic: {
MachineFunction &MF = *MBB.getParent();
unsigned CPI = I->getOperand(1).getIndex();
unsigned PCLabelId = duplicateCPV(MF, CPI);
I->getOperand(1).setIndex(CPI);
I->getOperand(2).setImm(PCLabelId);
break;
}
}
if (!I->isBundledWithSucc())
break;
++I;
}
return Cloned;
}
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::t2LDRLIT_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::t2LDRLIT_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;
Register Addr0 = MI0.getOperand(1).getReg();
Register Addr1 = MI1.getOperand(1).getReg();
if (Addr0 != Addr1) {
if (!MRI || !Addr0.isVirtual() || !Addr1.isVirtual())
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) {
// %12 = PICLDR %11, 0, 14, %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;
auto IsLoadOpcode = [&](unsigned Opcode) {
switch (Opcode) {
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:
return true;
}
};
if (!IsLoadOpcode(Load1->getMachineOpcode()) ||
!IsLoadOpcode(Load2->getMachineOpcode()))
return false;
// 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 together. 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.isDebugInstr())
return false;
// Terminators and labels can't be scheduled around.
if (MI.isTerminator() || MI.isPosition())
return true;
// INLINEASM_BR can jump to another block
if (MI.getOpcode() == TargetOpcode::INLINEASM_BR)
return true;
if (isSEHInstruction(MI))
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 debug instructions
while (++I != MBB->end() && I->isDebugInstr())
;
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, /*TRI=*/nullptr))
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().hasOptSize()) {
MachineBasicBlock *Pred = *MBB.pred_begin();
if (!Pred->empty()) {
MachineInstr *LastMI = &*Pred->rbegin();
if (LastMI->getOpcode() == ARM::t2Bcc) {
const TargetRegisterInfo *TRI = &getRegisterInfo();
MachineInstr *CmpMI = findCMPToFoldIntoCBZ(LastMI, TRI);
if (CmpMI)
return false;
}
}
}
return isProfitableToIfCvt(MBB, NumCycles, ExtraPredCycles,
MBB, 0, 0, Probability);
}
bool ARMBaseInstrInfo::
isProfitableToIfCvt(MachineBasicBlock &TBB,
unsigned TCycles, unsigned TExtra,
MachineBasicBlock &FBB,
unsigned FCycles, unsigned FExtra,
BranchProbability Probability) const {
if (!TCycles)
return false;
// In thumb code we often end up trading one branch for a IT block, and
// if we are cloning the instruction can increase code size. Prevent
// blocks with multiple predecessors from being ifcvted to prevent this
// cloning.
if (Subtarget.isThumb2() && TBB.getParent()->getFunction().hasMinSize()) {
if (TBB.pred_size() != 1 || FBB.pred_size() != 1)
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 PredCost = (TCycles + FCycles + TExtra + FExtra) * ScalingUpFactor;
unsigned UnpredCost;
if (!Subtarget.hasBranchPredictor()) {
// When we don't have a branch predictor it's always cheaper to not take a
// branch than take it, so we have to take that into account.
unsigned NotTakenBranchCost = 1;
unsigned TakenBranchCost = Subtarget.getMispredictionPenalty();
unsigned TUnpredCycles, FUnpredCycles;
if (!FCycles) {
// Triangle: TBB is the fallthrough
TUnpredCycles = TCycles + NotTakenBranchCost;
FUnpredCycles = TakenBranchCost;
} else {
// Diamond: TBB is the block that is branched to, FBB is the fallthrough
TUnpredCycles = TCycles + TakenBranchCost;
FUnpredCycles = FCycles + NotTakenBranchCost;
// The branch at the end of FBB will disappear when it's predicated, so
// discount it from PredCost.
PredCost -= 1 * ScalingUpFactor;
}
// The total cost is the cost of each path scaled by their probabilities
unsigned TUnpredCost = Probability.scale(TUnpredCycles * ScalingUpFactor);
unsigned FUnpredCost = Probability.getCompl().scale(FUnpredCycles * ScalingUpFactor);
UnpredCost = TUnpredCost + FUnpredCost;
// When predicating assume that the first IT can be folded away but later
// ones cost one cycle each
if (Subtarget.isThumb2() && TCycles + FCycles > 4) {
PredCost += ((TCycles + FCycles - 4) / 4) * ScalingUpFactor;
}
} else {
unsigned TUnpredCost = Probability.scale(TCycles * ScalingUpFactor);
unsigned FUnpredCost =
Probability.getCompl().scale(FCycles * ScalingUpFactor);
UnpredCost = TUnpredCost + FUnpredCost;
UnpredCost += 1 * ScalingUpFactor; // The branch itself
UnpredCost += Subtarget.getMispredictionPenalty() * ScalingUpFactor / 10;
}
return PredCost <= UnpredCost;
}
unsigned
ARMBaseInstrInfo::extraSizeToPredicateInstructions(const MachineFunction &MF,
unsigned NumInsts) const {
// Thumb2 needs a 2-byte IT instruction to predicate up to 4 instructions.
// ARM has a condition code field in every predicable instruction, using it
// doesn't change code size.
if (!Subtarget.isThumb2())
return 0;
// It's possible that the size of the IT is restricted to a single block.
unsigned MaxInsts = Subtarget.restrictIT() ? 1 : 4;
return divideCeil(NumInsts, MaxInsts) * 2;
}
unsigned
ARMBaseInstrInfo::predictBranchSizeForIfCvt(MachineInstr &MI) const {
// If this branch is likely to be folded into the comparison to form a
// CB(N)Z, then removing it won't reduce code size at all, because that will
// just replace the CB(N)Z with a CMP.
if (MI.getOpcode() == ARM::t2Bcc &&
findCMPToFoldIntoCBZ(&MI, &getRegisterInfo()))
return 0;
unsigned Size = getInstSizeInBytes(MI);
// For Thumb2, all branches are 32-bit instructions during the if conversion
// pass, but may be replaced with 16-bit instructions during size reduction.
// Since the branches considered by if conversion tend to be forward branches
// over small basic blocks, they are very likely to be in range for the
// narrow instructions, so we assume the final code size will be half what it
// currently is.
if (Subtarget.isThumb2())
Size /= 2;
return Size;
}
bool
ARMBaseInstrInfo::isProfitableToUnpredicate(MachineBasicBlock &TMBB,
MachineBasicBlock &FMBB) const {
// Reduce false anti-dependencies to let the target's out-of-order execution
// engine do its thing.
return Subtarget.isProfitableToUnpredicate();
}
/// 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,
Register &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.
Register PredReg;
ARMCC::CondCodes CC = getInstrPredicate(MI, PredReg);
// MOVCC AL can't be inverted. Shouldn't happen.
if (CC == ARMCC::AL || PredReg != ARM::CPSR)
return nullptr;
MachineInstr *CommutedMI =
TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
if (!CommutedMI)
return nullptr;
// After swapping the MOVCC operands, also invert the condition.
CommutedMI->getOperand(CommutedMI->findFirstPredOperandIdx())
.setImm(ARMCC::getOppositeCondition(CC));
return CommutedMI;
}
}
return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
}
/// Identify instructions that can be folded into a MOVCC instruction, and
/// return the defining instruction.
MachineInstr *
ARMBaseInstrInfo::canFoldIntoMOVCC(Register Reg, const MachineRegisterInfo &MRI,
const TargetInstrInfo *TII) const {
if (!Reg.isVirtual())
return nullptr;
if (!MRI.hasOneNonDBGUse(Reg))
return nullptr;
MachineInstr *MI = MRI.getVRegDef(Reg);
if (!MI)
return nullptr;
// Check if MI can be predicated and folded into the MOVCC.
if (!isPredicable(*MI))
return nullptr;
// Check if MI has any non-dead defs or physreg uses. This also detects
// predicated instructions which will be reading CPSR.
for (const MachineOperand &MO : llvm::drop_begin(MI->operands(), 1)) {
// 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 (MO.getReg().isPhysical())
return nullptr;
if (MO.isDef() && !MO.isDead())
return nullptr;
}
bool DontMoveAcrossStores = true;
if (!MI->isSafeToMove(DontMoveAcrossStores))
return nullptr;
return MI;
}
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);
MachineOperand TrueReg = MI.getOperand(Invert ? 1 : 2);
Register DestReg = MI.getOperand(0).getReg();
const TargetRegisterClass *FalseClass = MRI.getRegClass(FalseReg.getReg());
const TargetRegisterClass *TrueClass = MRI.getRegClass(TrueReg.getReg());
if (!MRI.constrainRegClass(DestReg, FalseClass))
return nullptr;
if (!MRI.constrainRegClass(DestReg, TrueClass))
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.operands()[i].isPredicate(); ++i)
NewMI.add(DefMI->getOperand(i));
unsigned CondCode = MI.getOperand(3).getImm();
if (Invert)
NewMI.addImm(ARMCC::getOppositeCondition(ARMCC::CondCodes(CondCode)));
else
NewMI.addImm(CondCode);
NewMI.add(MI.getOperand(4));
// DefMI is not the -S version that sets CPSR, so add an optional %noreg.
if (NewMI->hasOptionalDef())
NewMI.add(condCodeOp());
// 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.add(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 transferred 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::tADDSi3, ARM::tADDi3},
{ARM::tADDSi8, ARM::tADDi8},
{ARM::tADDSrr, ARM::tADDrr},
{ARM::tADCS, ARM::tADC},
{ARM::tSUBSi3, ARM::tSUBi3},
{ARM::tSUBSi8, ARM::tSUBi8},
{ARM::tSUBSrr, ARM::tSUBrr},
{ARM::tSBCS, ARM::tSBC},
{ARM::tRSBS, ARM::tRSB},
{ARM::tLSLSri, ARM::tLSLri},
{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 (const auto &Entry : AddSubFlagsOpcodeMap)
if (OldOpc == Entry.PseudoOpc)
return Entry.MachineOpc;
return 0;
}
void llvm::emitARMRegPlusImmediate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
const DebugLoc &dl, Register DestReg,
Register BaseReg, int NumBytes,
ARMCC::CondCodes Pred, Register PredReg,
const ARMBaseInstrInfo &TII,
unsigned MIFlags) {
if (NumBytes == 0 && DestReg != BaseReg) {
BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), DestReg)
.addReg(BaseReg, RegState::Kill)
.add(predOps(Pred, PredReg))
.add(condCodeOp())
.setMIFlags(MIFlags);
return;
}
bool isSub = NumBytes < 0;
if (isSub) NumBytes = -NumBytes;
while (NumBytes) {
unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
unsigned ThisVal = NumBytes & llvm::rotr<uint32_t>(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)
.add(predOps(Pred, PredReg))
.add(condCodeOp())
.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 (!Subtarget.hasMinSize())
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 RegsNeeded;
const TargetRegisterClass *RegClass;
if (IsVFPPushPop) {
RegsNeeded = NumBytes / 8;
RegClass = &ARM::DPRRegClass;
} else {
RegsNeeded = NumBytes / 4;
RegClass = &ARM::GPRRegClass;
}
// 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;
// We're also going to need the first register transferred by this
// instruction, which won't necessarily be the first register in the list.
unsigned FirstRegEnc = -1;
const TargetRegisterInfo *TRI = MF.getRegInfo().getTargetRegisterInfo();
for (int i = MI->getNumOperands() - 1; i >= RegListIdx; --i) {
MachineOperand &MO = MI->getOperand(i);
RegList.push_back(MO);
if (MO.isReg() && !MO.isImplicit() &&
TRI->getEncodingValue(MO.getReg()) < FirstRegEnc)
FirstRegEnc = TRI->getEncodingValue(MO.getReg());
}
const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
// Now try to find enough space in the reglist to allocate NumBytes.
for (int CurRegEnc = FirstRegEnc - 1; CurRegEnc >= 0 && RegsNeeded;
--CurRegEnc) {
MCRegister CurReg = RegClass->getRegister(CurRegEnc);
if (IsT1PushPop && CurRegEnc > TRI->getEncodingValue(ARM::R7))
continue;
if (!IsPop) {
// Pushing any register is completely harmless, mark the register involved
// as undef since we don't care about its value and must not restore it
// during stack unwinding.
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 (const MachineOperand &MO : llvm::reverse(RegList))
MIB.add(MO);
return true;
}
bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
Register 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 || Opcode == ARM::INLINEASM_BR)
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 immediate into this ADDri/SUBri
// as possible.
unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
unsigned ThisImmVal = Offset & llvm::rotr<uint32_t>(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;
case ARMII::AddrMode5FP16:
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 = 2;
break;
case ARMII::AddrModeT2_i7:
case ARMII::AddrModeT2_i7s2:
case ARMII::AddrModeT2_i7s4:
ImmIdx = FrameRegIdx+1;
InstrOffs = MI.getOperand(ImmIdx).getImm();
NumBits = 7;
Scale = (AddrMode == ARMII::AddrModeT2_i7s2 ? 2 :
AddrMode == ARMII::AddrModeT2_i7s4 ? 4 : 1);
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, Register &SrcReg,
Register &SrcReg2, int64_t &CmpMask,
int64_t &CmpValue) const {
switch (MI.getOpcode()) {
default: break;
case ARM::CMPri:
case ARM::t2CMPri:
case ARM::tCMPi8:
SrcReg = MI.getOperand(0).getReg();
SrcReg2 = 0;
CmpMask = ~0;
CmpValue = MI.getOperand(1).getImm();
return true;
case ARM::CMPrr:
case ARM::t2CMPrr:
case ARM::tCMPr:
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, Register 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;
}
/// getCmpToAddCondition - assume the flags are set by CMP(a,b), return
/// the condition code if we modify the instructions such that flags are
/// set by ADD(a,b,X).
inline static ARMCC::CondCodes getCmpToAddCondition(ARMCC::CondCodes CC) {
switch (CC) {
default: return ARMCC::AL;
case ARMCC::HS: return ARMCC::LO;
case ARMCC::LO: return ARMCC::HS;
case ARMCC::VS: return ARMCC::VS;
case ARMCC::VC: return ARMCC::VC;
}
}
/// 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.
/// CMPrr(r0, r1) can be made redundant by ADDr[ri](r0, r1, X).
/// This function can be extended later on.
inline static bool isRedundantFlagInstr(const MachineInstr *CmpI,
Register SrcReg, Register SrcReg2,
int64_t ImmValue,
const MachineInstr *OI,
bool &IsThumb1) {
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))) {
IsThumb1 = false;
return true;
}
if (CmpI->getOpcode() == ARM::tCMPr && OI->getOpcode() == ARM::tSUBrr &&
((OI->getOperand(2).getReg() == SrcReg &&
OI->getOperand(3).getReg() == SrcReg2) ||
(OI->getOperand(2).getReg() == SrcReg2 &&
OI->getOperand(3).getReg() == SrcReg))) {
IsThumb1 = true;
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) {
IsThumb1 = false;
return true;
}
if (CmpI->getOpcode() == ARM::tCMPi8 &&
(OI->getOpcode() == ARM::tSUBi8 || OI->getOpcode() == ARM::tSUBi3) &&
OI->getOperand(2).getReg() == SrcReg &&
OI->getOperand(3).getImm() == ImmValue) {
IsThumb1 = true;
return true;
}
if ((CmpI->getOpcode() == ARM::CMPrr || CmpI->getOpcode() == ARM::t2CMPrr) &&
(OI->getOpcode() == ARM::ADDrr || OI->getOpcode() == ARM::t2ADDrr ||
OI->getOpcode() == ARM::ADDri || OI->getOpcode() == ARM::t2ADDri) &&
OI->getOperand(0).isReg() && OI->getOperand(1).isReg() &&
OI->getOperand(0).getReg() == SrcReg &&
OI->getOperand(1).getReg() == SrcReg2) {
IsThumb1 = false;
return true;
}
if (CmpI->getOpcode() == ARM::tCMPr &&
(OI->getOpcode() == ARM::tADDi3 || OI->getOpcode() == ARM::tADDi8 ||
OI->getOpcode() == ARM::tADDrr) &&
OI->getOperand(0).getReg() == SrcReg &&
OI->getOperand(2).getReg() == SrcReg2) {
IsThumb1 = true;
return true;
}
return false;
}
static bool isOptimizeCompareCandidate(MachineInstr *MI, bool &IsThumb1) {
switch (MI->getOpcode()) {
default: return false;
case ARM::tLSLri:
case ARM::tLSRri:
case ARM::tLSLrr:
case ARM::tLSRrr:
case ARM::tSUBrr:
case ARM::tADDrr:
case ARM::tADDi3:
case ARM::tADDi8:
case ARM::tSUBi3:
case ARM::tSUBi8:
case ARM::tMUL:
case ARM::tADC:
case ARM::tSBC:
case ARM::tRSB:
case ARM::tAND:
case ARM::tORR:
case ARM::tEOR:
case ARM::tBIC:
case ARM::tMVN:
case ARM::tASRri:
case ARM::tASRrr:
case ARM::tROR:
IsThumb1 = true;
[[fallthrough]];
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::ANDrsr:
case ARM::ANDrsi:
case ARM::t2ANDrr:
case ARM::t2ANDri:
case ARM::t2ANDrs:
case ARM::ORRrr:
case ARM::ORRri:
case ARM::ORRrsr:
case ARM::ORRrsi:
case ARM::t2ORRrr:
case ARM::t2ORRri:
case ARM::t2ORRrs:
case ARM::EORrr:
case ARM::EORri:
case ARM::EORrsr:
case ARM::EORrsi:
case ARM::t2EORrr:
case ARM::t2EORri:
case ARM::t2EORrs:
case ARM::BICri:
case ARM::BICrr:
case ARM::BICrsi:
case ARM::BICrsr:
case ARM::t2BICri:
case ARM::t2BICrr:
case ARM::t2BICrs:
case ARM::t2LSRri:
case ARM::t2LSRrr:
case ARM::t2LSLri:
case ARM::t2LSLrr:
case ARM::MOVsr:
case ARM::MOVsi:
return true;
}
}
/// 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, Register SrcReg, Register SrcReg2, int64_t CmpMask,
int64_t 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 or ADD instruction.
// For CMPrr(r1,r2), we are looking for SUB(r1,r2), SUB(r2,r1), or
// ADDr[ri](r1, r2, X).
// For CMPri(r1, CmpValue), we are looking for SUBri(r1, CmpValue).
MachineInstr *SubAdd = 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 SubAdd may still be a candidate.
// Thus we cannot return here.
if (CmpInstr.getOpcode() == ARM::CMPri ||
CmpInstr.getOpcode() == ARM::t2CMPri ||
CmpInstr.getOpcode() == ARM::tCMPi8)
MI = nullptr;
else
return false;
}
bool IsThumb1 = false;
if (MI && !isOptimizeCompareCandidate(MI, IsThumb1))
return false;
// We also want to do this peephole for cases like this: if (a*b == 0),
// and optimise away the CMP instruction from the generated code sequence:
// MULS, MOVS, MOVS, CMP. Here the MOVS instructions load the boolean values
// resulting from the select instruction, but these MOVS instructions for
// Thumb1 (V6M) are flag setting and are thus preventing this optimisation.
// However, if we only have MOVS instructions in between the CMP and the
// other instruction (the MULS in this example), then the CPSR is dead so we
// can safely reorder the sequence into: MOVS, MOVS, MULS, CMP. We do this
// reordering and then continue the analysis hoping we can eliminate the
// CMP. This peephole works on the vregs, so is still in SSA form. As a
// consequence, the movs won't redefine/kill the MUL operands which would
// make this reordering illegal.
const TargetRegisterInfo *TRI = &getRegisterInfo();
if (MI && IsThumb1) {
--I;
if (I != E && !MI->readsRegister(ARM::CPSR, TRI)) {
bool CanReorder = true;
for (; I != E; --I) {
if (I->getOpcode() != ARM::tMOVi8) {
CanReorder = false;
break;
}
}
if (CanReorder) {
MI = MI->removeFromParent();
E = CmpInstr;
CmpInstr.getParent()->insert(E, MI);
}
}
I = CmpInstr;
E = MI;
}
// Check that CPSR isn't set between the comparison instruction and the one we
// want to change. At the same time, search for SubAdd.
bool SubAddIsThumb1 = false;
do {
const MachineInstr &Instr = *--I;
// Check whether CmpInstr can be made redundant by the current instruction.
if (isRedundantFlagInstr(&CmpInstr, SrcReg, SrcReg2, CmpValue, &Instr,
SubAddIsThumb1)) {
SubAdd = &*I;
break;
}
// Allow E (which was initially MI) to be SubAdd but do not search before E.
if (I == E)
break;
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;
if (I == B) {
// In some cases, we scan the use-list of an instruction for an AND;
// that AND is in the same BB, but may not be scheduled before the
// corresponding TST. In that case, bail out.
//
// FIXME: We could try to reschedule the AND.
return false;
}
} while (true);
// Return false if no candidates exist.
if (!MI && !SubAdd)
return false;
// If we found a SubAdd, use it as it will be closer to the CMP
if (SubAdd) {
MI = SubAdd;
IsThumb1 = SubAddIsThumb1;
}
// We can't use a predicated instruction - it doesn't always write the flags.
if (isPredicated(*MI))
return false;
// 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:
case ARM::VSELEQH:
CC = ARMCC::EQ;
break;
case ARM::VSELGTD:
case ARM::VSELGTS:
case ARM::VSELGTH:
CC = ARMCC::GT;
break;
case ARM::VSELGED:
case ARM::VSELGES:
case ARM::VSELGEH:
CC = ARMCC::GE;
break;
case ARM::VSELVSD:
case ARM::VSELVSS:
case ARM::VSELVSH:
CC = ARMCC::VS;
break;
}
if (SubAdd) {
// 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.
// If we have ADD(r1, r2, X) and CMP(r1, r2), the condition code also
// needs to be modified.
// Push the condition code operands to OperandsToUpdate.
// If it is safe to remove CmpInstr, the condition code of these
// operands will be modified.
unsigned Opc = SubAdd->getOpcode();
bool IsSub = Opc == ARM::SUBrr || Opc == ARM::t2SUBrr ||
Opc == ARM::SUBri || Opc == ARM::t2SUBri ||
Opc == ARM::tSUBrr || Opc == ARM::tSUBi3 ||
Opc == ARM::tSUBi8;
unsigned OpI = Opc != ARM::tSUBrr ? 1 : 2;
if (!IsSub ||
(SrcReg2 != 0 && SubAdd->getOperand(OpI).getReg() == SrcReg2 &&
SubAdd->getOperand(OpI + 1).getReg() == SrcReg)) {
// VSel doesn't support condition code update.
if (IsInstrVSel)
return false;
// Ensure we can swap the condition.
ARMCC::CondCodes NewCC = (IsSub ? getSwappedCondition(CC) : getCmpToAddCondition(CC));
if (NewCC == ARMCC::AL)
return false;
OperandsToUpdate.push_back(
std::make_pair(&((*I).getOperand(IO - 1)), NewCC));
}
} else {
// No SubAdd, 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 : MBB->successors())
if (Succ->isLiveIn(ARM::CPSR))
return false;
}
// Toggle the optional operand to CPSR (if it exists - in Thumb1 we always
// set CPSR so this is represented as an explicit output)
if (!IsThumb1) {
unsigned CPSRRegNum = MI->getNumExplicitOperands() - 1;
MI->getOperand(CPSRRegNum).setReg(ARM::CPSR);
MI->getOperand(CPSRRegNum).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 (auto &[MO, Cond] : OperandsToUpdate)
MO->setImm(Cond);
MI->clearRegisterDeads(ARM::CPSR);
return true;
}
bool ARMBaseInstrInfo::shouldSink(const MachineInstr &MI) const {
// Do not sink MI if it might be used to optimize a redundant compare.
// We heuristically only look at the instruction immediately following MI to
// avoid potentially searching the entire basic block.
if (isPredicated(MI))
return true;
MachineBasicBlock::const_iterator Next = &MI;
++Next;
Register SrcReg, SrcReg2;
int64_t CmpMask, CmpValue;
bool IsThumb1;
if (Next != MI.getParent()->end() &&
analyzeCompare(*Next, SrcReg, SrcReg2, CmpMask, CmpValue) &&
isRedundantFlagInstr(&*Next, SrcReg, SrcReg2, CmpValue, &MI, IsThumb1))
return false;
return true;
}
bool ARMBaseInstrInfo::foldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
Register Reg,
MachineRegisterInfo *MRI) const {
// Fold large immediates into add, sub, or, xor.
unsigned DefOpc = DefMI.getOpcode();
if (DefOpc != ARM::t2MOVi32imm && DefOpc != ARM::MOVi32imm &&
DefOpc != ARM::tMOVi32imm)
return false;
if (!DefMI.getOperand(1).isImm())
// Could be t2MOVi32imm @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.
const bool ToSP = DefMI.getOperand(0).getReg() == ARM::SP;
const unsigned t2ADD = ToSP ? ARM::t2ADDspImm : ARM::t2ADDri;
const unsigned t2SUB = ToSP ? ARM::t2SUBspImm : ARM::t2SUBri;
if (ARM_AM::isT2SOImmTwoPartVal(ImmVal))
NewUseOpc = UseOpc == ARM::t2ADDrr ? t2ADD : t2SUB;
else if (ARM_AM::isT2SOImmTwoPartVal(-ImmVal)) {
ImmVal = -ImmVal;
NewUseOpc = UseOpc == ARM::t2ADDrr ? t2SUB : t2ADD;
} 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;
Register Reg1 = UseMI.getOperand(OpIdx).getReg();
bool isKill = UseMI.getOperand(OpIdx).isKill();
const TargetRegisterClass *TRC = MRI->getRegClass(Reg);
Register NewReg = MRI->createVirtualRegister(TRC);
BuildMI(*UseMI.getParent(), UseMI, UseMI.getDebugLoc(), get(NewUseOpc),
NewReg)
.addReg(Reg1, getKillRegState(isKill))
.addImm(SOImmValV1)
.add(predOps(ARMCC::AL))
.add(condCodeOp());
UseMI.setDesc(get(NewUseOpc));
UseMI.getOperand(1).setReg(NewReg);
UseMI.getOperand(1).setIsKill();
UseMI.getOperand(2).ChangeToImmediate(SOImmValV2);
DefMI.eraseFromParent();
// FIXME: t2ADDrr should be split, as different rulles apply when writing to SP.
// Just as t2ADDri, that was split to [t2ADDri, t2ADDspImm].
// Then the below code will not be needed, as the input/output register
// classes will be rgpr or gprSP.
// For now, we fix the UseMI operand explicitly here:
switch(NewUseOpc){
case ARM::t2ADDspImm:
case ARM::t2SUBspImm:
case ARM::t2ADDri:
case ARM::t2SUBri:
MRI->constrainRegClass(UseMI.getOperand(0).getReg(), TRC);
}
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: {
Register Rt = MI.getOperand(0).getReg();
Register Rm = MI.getOperand(3).getReg();
return (Rt == Rm) ? 4 : 3;
}
case ARM::LDR_PRE_REG:
case ARM::LDRB_PRE_REG: {
Register Rt = MI.getOperand(0).getReg();
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register 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: {
Register Rm = MI.getOperand(3).getReg();
if (Rm == 0)
return 3;
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register Rn = MI.getOperand(2).getReg();
Register 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: {
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register Rn = MI.getOperand(3).getReg();
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register Rn = MI.getOperand(3).getReg();
return (Rt == Rn) ? 4 : 3;
}
case ARM::STRD_PRE: {
Register 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: {
Register Rt = MI.getOperand(0).getReg();
Register 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().getValue();
}
// FIXME: The scheduler currently can't handle values larger than 16. But
// the values can actually go up to 32 for floating-point load/store
// multiple (VLDMIA etc.). Also, the way this code is reasoning about memory
// operations isn't right; we could end up with "extra" memory operands for
// various reasons, like tail merge merging two memory operations.
return std::min(Size / 4, 16U);
}
static unsigned getNumMicroOpsSingleIssuePlusExtras(unsigned Opc,
unsigned NumRegs) {
unsigned UOps = 1 + NumRegs; // 1 for address computation.
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;
}
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;
switch (Subtarget.getLdStMultipleTiming()) {
case ARMSubtarget::SingleIssuePlusExtras:
return getNumMicroOpsSingleIssuePlusExtras(Opc, NumRegs);
case ARMSubtarget::SingleIssue:
// Assume the worst.
return NumRegs;
case ARMSubtarget::DoubleIssue: {
if (NumRegs < 4)
return 2;
// 4 registers would be issued: 2, 2.
// 5 registers would be issued: 2, 2, 1.
unsigned UOps = (NumRegs / 2);
if (NumRegs % 2)
++UOps;
return UOps;
}
case ARMSubtarget::DoubleIssueCheckUnalignedAccess: {
unsigned UOps = (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())->getAlign() < Align(8))
++UOps;
return UOps;
}
}
}
}
llvm_unreachable("Didn't find the number of microops");
}
std::optional<unsigned>
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);
unsigned 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;
}
std::optional<unsigned>
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);
unsigned 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;
}
std::optional<unsigned>
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);
unsigned 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;
}
std::optional<unsigned>
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);
unsigned 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;
}
std::optional<unsigned> 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.
std::optional<unsigned> DefCycle;
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 = true;
DefCycle = getLDMDefCycle(ItinData, DefMCID, DefClass, DefIdx, DefAlign);
break;
}
if (!DefCycle)
// We can't seem to determine the result latency of the def, assume it's 2.
DefCycle = 2;
std::optional<unsigned> UseCycle;
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)
// Assume it's read in the first stage.
UseCycle = 1;
if (UseCycle > *DefCycle + 1)
return std::nullopt;
UseCycle = *DefCycle - *UseCycle + 1;
if (UseCycle > 0u) {
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 = *UseCycle - 1;
} else if (ItinData->hasPipelineForwarding(DefClass, DefIdx,
UseClass, UseIdx)) {
UseCycle = *UseCycle - 1;
}
}
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, TRI, false, true);
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, TRI, false);
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.checkVLDnAccessAlignment()) {
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;
}
std::optional<unsigned> 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 std::nullopt;
const MachineOperand &DefMO = DefMI.getOperand(DefIdx);
Register Reg = DefMO.getReg();
const MachineInstr *ResolvedDefMI = &DefMI;
unsigned DefAdj = 0;
if (DefMI.isBundle())
ResolvedDefMI =
getBundledDefMI(&getRegisterInfo(), &DefMI, Reg, DefIdx, DefAdj);
if (ResolvedDefMI->isCopyLike() || ResolvedDefMI->isInsertSubreg() ||
ResolvedDefMI->isRegSequence() || ResolvedDefMI->isImplicitDef()) {
return 1;
}
const MachineInstr *ResolvedUseMI = &UseMI;
unsigned UseAdj = 0;
if (UseMI.isBundle()) {
ResolvedUseMI =
getBundledUseMI(&getRegisterInfo(), UseMI, Reg, UseIdx, UseAdj);
if (!ResolvedUseMI)
return std::nullopt;
}
return getOperandLatencyImpl(
ItinData, *ResolvedDefMI, DefIdx, ResolvedDefMI->getDesc(), DefAdj, DefMO,
Reg, *ResolvedUseMI, UseIdx, ResolvedUseMI->getDesc(), UseAdj);
}
std::optional<unsigned> ARMBaseInstrInfo::getOperandLatencyImpl(
const InstrItineraryData *ItinData, const MachineInstr &DefMI,
unsigned DefIdx, const MCInstrDesc &DefMCID, unsigned DefAdj,
const MachineOperand &DefMO, unsigned Reg, const MachineInstr &UseMI,
unsigned UseIdx, const MCInstrDesc &UseMCID, unsigned UseAdj) const {
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();
if (MF->getFunction().hasOptSize())
--Latency;
}
return Latency;
}
if (DefMO.isImplicit() || UseMI.getOperand(UseIdx).isImplicit())
return std::nullopt;
unsigned DefAlign = DefMI.hasOneMemOperand()
? (*DefMI.memoperands_begin())->getAlign().value()
: 0;
unsigned UseAlign = UseMI.hasOneMemOperand()
? (*UseMI.memoperands_begin())->getAlign().value()
: 0;
// Get the itinerary's latency if possible, and handle variable_ops.
std::optional<unsigned> Latency = getOperandLatency(
ItinData, DefMCID, DefIdx, DefAlign, UseMCID, UseIdx, UseAlign);
// Unable to find operand latency. The caller may resort to getInstrLatency.
if (!Latency)
return std::nullopt;
// 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;
}
std::optional<unsigned>
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()) {
std::optional<unsigned> Latency =
ItinData->getOperandCycle(DefMCID.getSchedClass(), DefIdx);
int Adj = Subtarget.getPreISelOperandLatencyAdjustment();
int Threshold = 1 + Adj;
return !Latency || Latency <= (unsigned)Threshold ? 1 : *Latency - Adj;
}
const MCInstrDesc &UseMCID = get(UseNode->getMachineOpcode());
auto *DefMN = cast<MachineSDNode>(DefNode);
unsigned DefAlign = !DefMN->memoperands_empty()
? (*DefMN->memoperands_begin())->getAlign().value()
: 0;
auto *UseMN = cast<MachineSDNode>(UseNode);
unsigned UseAlign = !UseMN->memoperands_empty()
? (*UseMN->memoperands_begin())->getAlign().value()
: 0;
std::optional<unsigned> Latency = getOperandLatency(
ItinData, DefMCID, DefIdx, DefAlign, UseMCID, UseIdx, UseAlign);
if (!Latency)
return std::nullopt;
if (Latency > 1U &&
(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 = DefNode->getConstantOperandVal(2);
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (ShImm == 0 ||
(ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
Latency = *Latency - 1;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs: {
// Thumb2 mode: lsl only.
unsigned ShAmt = DefNode->getConstantOperandVal(2);
if (ShAmt == 0 || ShAmt == 2)
Latency = *Latency - 1;
break;
}
}
} else if (DefIdx == 0 && Latency > 2U && 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 = DefNode->getConstantOperandVal(2);
unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
if (ShImm == 0 ||
((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
Latency = *Latency - 2;
else if (ShImm == 1 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsr)
Latency = *Latency - 1;
break;
}
case ARM::t2LDRs:
case ARM::t2LDRBs:
case ARM::t2LDRHs:
case ARM::t2LDRSHs:
// Thumb2 mode: lsl 0-3 only.
Latency = *Latency - 2;
break;
}
}
if (DefAlign < 8 && Subtarget.checkVLDnAccessAlignment())
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::VLD1d8TPseudo:
case ARM::VLD1d16TPseudo:
case ARM::VLD1d32TPseudo:
case ARM::VLD1d64TPseudo:
case ARM::VLD1d64TPseudoWB_fixed:
case ARM::VLD1d64TPseudoWB_register:
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::VLD1d8QPseudo:
case ARM::VLD1d16QPseudo:
case ARM::VLD1d32QPseudo:
case ARM::VLD1d64QPseudo:
case ARM::VLD1d64QPseudoWB_fixed:
case ARM::VLD1d64QPseudoWB_register:
case ARM::VLD1q8HighQPseudo:
case ARM::VLD1q8LowQPseudo_UPD:
case ARM::VLD1q8HighTPseudo:
case ARM::VLD1q8LowTPseudo_UPD:
case ARM::VLD1q16HighQPseudo:
case ARM::VLD1q16LowQPseudo_UPD:
case ARM::VLD1q16HighTPseudo:
case ARM::VLD1q16LowTPseudo_UPD:
case ARM::VLD1q32HighQPseudo:
case ARM::VLD1q32LowQPseudo_UPD:
case ARM::VLD1q32HighTPseudo:
case ARM::VLD1q32LowTPseudo_UPD:
case ARM::VLD1q64HighQPseudo:
case ARM::VLD1q64LowQPseudo_UPD:
case ARM::VLD1q64HighTPseudo:
case ARM::VLD1q64LowTPseudo_UPD:
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::VLD2DUPq8EvenPseudo:
case ARM::VLD2DUPq8OddPseudo:
case ARM::VLD2DUPq16EvenPseudo:
case ARM::VLD2DUPq16OddPseudo:
case ARM::VLD2DUPq32EvenPseudo:
case ARM::VLD2DUPq32OddPseudo:
case ARM::VLD3DUPq8EvenPseudo:
case ARM::VLD3DUPq8OddPseudo:
case ARM::VLD3DUPq16EvenPseudo:
case ARM::VLD3DUPq16OddPseudo:
case ARM::VLD3DUPq32EvenPseudo:
case ARM::VLD3DUPq32OddPseudo:
case ARM::VLD4DUPd8Pseudo:
case ARM::VLD4DUPd16Pseudo:
case ARM::VLD4DUPd32Pseudo:
case ARM::VLD4DUPd8Pseudo_UPD:
case ARM::VLD4DUPd16Pseudo_UPD:
case ARM::VLD4DUPd32Pseudo_UPD:
case ARM::VLD4DUPq8EvenPseudo:
case ARM::VLD4DUPq8OddPseudo:
case ARM::VLD4DUPq16EvenPseudo:
case ARM::VLD4DUPq16OddPseudo:
case ARM::VLD4DUPq32EvenPseudo:
case ARM::VLD4DUPq32OddPseudo:
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 = *Latency + 1;
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) &&
!Subtarget.cheapPredicableCPSRDef())) {
// 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) &&
!Subtarget.cheapPredicableCPSRDef()))) {
// 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())->getAlign().value() : 0;
int Adj = adjustDefLatency(Subtarget, MI, MCID, DefAlign);
if (Adj >= 0 || (int)Latency > -Adj) {
return Latency + Adj;
}
return Latency;
}
unsigned 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.nonpipelinedVFP() &&
(DDomain == ARMII::DomainVFP || UDomain == ARMII::DomainVFP))
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();
std::optional<unsigned> DefCycle =
ItinData->getOperandCycle(DefClass, DefIdx);
return DefCycle && DefCycle <= 2U;
}
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;
}
if (MI.getOpcode() == ARM::tMOVr && !Subtarget.hasV6Ops()) {
// Make sure we don't generate a lo-lo mov that isn't supported.
if (!ARM::hGPRRegClass.contains(MI.getOperand(0).getReg()) &&
!ARM::hGPRRegClass.contains(MI.getOperand(1).getReg())) {
ErrInfo = "Non-flag-setting Thumb1 mov is v6-only";
return false;
}
}
if (MI.getOpcode() == ARM::tPUSH ||
MI.getOpcode() == ARM::tPOP ||
MI.getOpcode() == ARM::tPOP_RET) {
for (const MachineOperand &MO : llvm::drop_begin(MI.operands(), 2)) {
if (MO.isImplicit() || !MO.isReg())
continue;
Register Reg = MO.getReg();
if (Reg < ARM::R0 || Reg > ARM::R7) {
if (!(MI.getOpcode() == ARM::tPUSH && Reg == ARM::LR) &&
!(MI.getOpcode() == ARM::tPOP_RET && Reg == ARM::PC)) {
ErrInfo = "Unsupported register in Thumb1 push/pop";
return false;
}
}
}
}
if (MI.getOpcode() == ARM::MVE_VMOV_q_rr) {
assert(MI.getOperand(4).isImm() && MI.getOperand(5).isImm());
if ((MI.getOperand(4).getImm() != 2 && MI.getOperand(4).getImm() != 3) ||
MI.getOperand(4).getImm() != MI.getOperand(5).getImm() + 2) {
ErrInfo = "Incorrect array index for MVE_VMOV_q_rr";
return false;
}
}
// Check the address model by taking the first Imm operand and checking it is
// legal for that addressing mode.
ARMII::AddrMode AddrMode =
(ARMII::AddrMode)(MI.getDesc().TSFlags & ARMII::AddrModeMask);
switch (AddrMode) {
default:
break;
case ARMII::AddrModeT2_i7:
case ARMII::AddrModeT2_i7s2:
case ARMII::AddrModeT2_i7s4:
case ARMII::AddrModeT2_i8:
case ARMII::AddrModeT2_i8pos:
case ARMII::AddrModeT2_i8neg:
case ARMII::AddrModeT2_i8s4:
case ARMII::AddrModeT2_i12: {
uint32_t Imm = 0;
for (auto Op : MI.operands()) {
if (Op.isImm()) {
Imm = Op.getImm();
break;
}
}
if (!isLegalAddressImm(MI.getOpcode(), Imm, this)) {
ErrInfo = "Incorrect AddrMode Imm for instruction";
return false;
}
break;
}
}
return true;
}
void ARMBaseInstrInfo::expandLoadStackGuardBase(MachineBasicBlock::iterator MI,
unsigned LoadImmOpc,
unsigned LoadOpc) const {
assert(!Subtarget.isROPI() && !Subtarget.isRWPI() &&
"ROPI/RWPI not currently supported with stack guard");
MachineBasicBlock &MBB = *MI->getParent();
DebugLoc DL = MI->getDebugLoc();
Register Reg = MI->getOperand(0).getReg();
MachineInstrBuilder MIB;
unsigned int Offset = 0;
if (LoadImmOpc == ARM::MRC || LoadImmOpc == ARM::t2MRC) {
assert(!Subtarget.isReadTPSoft() &&
"TLS stack protector requires hardware TLS register");
BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
.addImm(15)
.addImm(0)
.addImm(13)
.addImm(0)
.addImm(3)
.add(predOps(ARMCC::AL));
Module &M = *MBB.getParent()->getFunction().getParent();
Offset = M.getStackProtectorGuardOffset();
if (Offset & ~0xfffU) {
// The offset won't fit in the LDR's 12-bit immediate field, so emit an
// extra ADD to cover the delta. This gives us a guaranteed 8 additional
// bits, resulting in a range of 0 to +1 MiB for the guard offset.
unsigned AddOpc = (LoadImmOpc == ARM::MRC) ? ARM::ADDri : ARM::t2ADDri;
BuildMI(MBB, MI, DL, get(AddOpc), Reg)
.addReg(Reg, RegState::Kill)
.addImm(Offset & ~0xfffU)
.add(predOps(ARMCC::AL))
.addReg(0);
Offset &= 0xfffU;
}
} else {
const GlobalValue *GV =
cast<GlobalValue>((*MI->memoperands_begin())->getValue());
bool IsIndirect = Subtarget.isGVIndirectSymbol(GV);
unsigned TargetFlags = ARMII::MO_NO_FLAG;
if (Subtarget.isTargetMachO()) {
TargetFlags |= ARMII::MO_NONLAZY;
} else if (Subtarget.isTargetCOFF()) {
if (GV->hasDLLImportStorageClass())
TargetFlags |= ARMII::MO_DLLIMPORT;
else if (IsIndirect)
TargetFlags |= ARMII::MO_COFFSTUB;
} else if (IsIndirect) {
TargetFlags |= ARMII::MO_GOT;
}
if (LoadImmOpc == ARM::tMOVi32imm) { // Thumb-1 execute-only
Register CPSRSaveReg = ARM::R12; // Use R12 as scratch register
auto APSREncoding =
ARMSysReg::lookupMClassSysRegByName("apsr_nzcvq")->Encoding;
BuildMI(MBB, MI, DL, get(ARM::t2MRS_M), CPSRSaveReg)
.addImm(APSREncoding)
.add(predOps(ARMCC::AL));
BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
.addGlobalAddress(GV, 0, TargetFlags);
BuildMI(MBB, MI, DL, get(ARM::t2MSR_M))
.addImm(APSREncoding)
.addReg(CPSRSaveReg, RegState::Kill)
.add(predOps(ARMCC::AL));
} else {
BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
.addGlobalAddress(GV, 0, TargetFlags);
}
if (IsIndirect) {
MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
MIB.addReg(Reg, RegState::Kill).addImm(0);
auto Flags = MachineMemOperand::MOLoad |
MachineMemOperand::MODereferenceable |
MachineMemOperand::MOInvariant;
MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
MachinePointerInfo::getGOT(*MBB.getParent()), Flags, 4, Align(4));
MIB.addMemOperand(MMO).add(predOps(ARMCC::AL));
}
}
MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
MIB.addReg(Reg, RegState::Kill)
.addImm(Offset)
.cloneMemRefs(*MI)
.add(predOps(ARMCC::AL));
}
bool
ARMBaseInstrInfo::isFpMLxInstruction(unsigned Opcode, unsigned &MulOpc,
unsigned &AddSubOpc,
bool &NegAcc, bool &HasLane) const {
auto 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.useNEONForFPMovs() && !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 MCRegister getCorrespondingDRegAndLane(const TargetRegisterInfo *TRI,
unsigned SReg, unsigned &Lane) {
MCRegister DReg =
TRI->getMatchingSuperReg(SReg, ARM::ssub_0, &ARM::DPRRegClass);
Lane = 0;
if (DReg)
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, MCRegister DReg,
unsigned Lane,
MCRegister &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 = MCRegister();
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 = MCRegister();
return true;
}
void ARMBaseInstrInfo::setExecutionDomain(MachineInstr &MI,
unsigned Domain) const {
unsigned DstReg, SrcReg;
MCRegister 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));
MIB.addReg(DstReg, RegState::Define)
.addReg(SrcReg)
.addReg(SrcReg)
.add(predOps(ARMCC::AL));
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));
MIB.addReg(DstReg, RegState::Define)
.addReg(DReg, RegState::Undef)
.addImm(Lane)
.add(predOps(ARMCC::AL));
// 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);
MCRegister 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)
.add(predOps(ARMCC::AL));
// The narrower destination must be marked as set to keep previous chains
// in place.
MIB.addReg(DstReg, RegState::Define | RegState::Implicit);
if (ImplicitSReg)
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;
MCRegister DDst, DSrc;
DDst = getCorrespondingDRegAndLane(TRI, DstReg, DstLane);
DSrc = getCorrespondingDRegAndLane(TRI, SrcReg, SrcLane);
MCRegister 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)
.add(predOps(ARMCC::AL));
// 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)
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>.
MCRegister 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))
.addImm(1)
.add(predOps(ARMCC::AL));
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))
.addImm(1)
.add(predOps(ARMCC::AL));
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 {
auto PartialUpdateClearance = Subtarget.getPartialUpdateClearance();
if (!PartialUpdateClearance)
return 0;
assert(TRI && "Need TRI instance");
const MachineOperand &MO = MI.getOperand(OpNum);
if (MO.readsReg())
return 0;
Register 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, TRI, false);
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 (Reg.isVirtual()) {
// Virtual register must be a def undef foo:ssub_0 operand.
if (!MO.getSubReg() || MI.readsVirtualRegister(Reg))
return 0;
} else if (ARM::SPRRegClass.contains(Reg)) {
// Physical register: MI must define the full D-reg.
MCRegister 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 PartialUpdateClearance;
}
// Break a partial register dependency after getPartialRegUpdateClearance
// returned non-zero.
void ARMBaseInstrInfo::breakPartialRegDependency(
MachineInstr &MI, unsigned OpNum, const TargetRegisterInfo *TRI) const {
assert(OpNum < MI.getDesc().getNumDefs() && "OpNum is not a def");
assert(TRI && "Need TRI instance");
const MachineOperand &MO = MI.getOperand(OpNum);
Register Reg = MO.getReg();
assert(Reg.isPhysical() && "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.
BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), get(ARM::FCONSTD), DReg)
.addImm(96)
.add(predOps(ARMCC::AL));
MI.addRegisterKilled(DReg, TRI, true);
}
bool ARMBaseInstrInfo::hasNOP() const {
return Subtarget.hasFeature(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);
if (!MOReg->isUndef())
InputRegs.push_back(RegSubRegPairAndIdx(MOReg->getReg(),
MOReg->getSubReg(), ARM::ssub_0));
// rZ
MOReg = &MI.getOperand(2);
if (!MOReg->isUndef())
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);
if (MOReg.isUndef())
return false;
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:
case ARM::MVE_VMOV_to_lane_32:
// dX = VSETLNi32 dY, rZ, imm
// qX = MVE_VMOV_to_lane_32 qY, rZ, imm
const MachineOperand &MOBaseReg = MI.getOperand(1);
const MachineOperand &MOInsertedReg = MI.getOperand(2);
if (MOInsertedReg.isUndef())
return false;
const MachineOperand &MOIndex = MI.getOperand(3);
BaseReg.Reg = MOBaseReg.getReg();
BaseReg.SubReg = MOBaseReg.getSubReg();
InsertedReg.Reg = MOInsertedReg.getReg();
InsertedReg.SubReg = MOInsertedReg.getSubReg();
InsertedReg.SubIdx = ARM::ssub_0 + MOIndex.getImm();
return true;
}
llvm_unreachable("Target dependent opcode missing");
}
std::pair<unsigned, unsigned>
ARMBaseInstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
const unsigned Mask = ARMII::MO_OPTION_MASK;
return std::make_pair(TF & Mask, TF & ~Mask);
}
ArrayRef<std::pair<unsigned, const char *>>
ARMBaseInstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
using namespace ARMII;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_LO16, "arm-lo16"}, {MO_HI16, "arm-hi16"},
{MO_LO_0_7, "arm-lo-0-7"}, {MO_HI_0_7, "arm-hi-0-7"},
{MO_LO_8_15, "arm-lo-8-15"}, {MO_HI_8_15, "arm-hi-8-15"},
};
return ArrayRef(TargetFlags);
}
ArrayRef<std::pair<unsigned, const char *>>
ARMBaseInstrInfo::getSerializableBitmaskMachineOperandTargetFlags() const {
using namespace ARMII;
static const std::pair<unsigned, const char *> TargetFlags[] = {
{MO_COFFSTUB, "arm-coffstub"},
{MO_GOT, "arm-got"},
{MO_SBREL, "arm-sbrel"},
{MO_DLLIMPORT, "arm-dllimport"},
{MO_SECREL, "arm-secrel"},
{MO_NONLAZY, "arm-nonlazy"}};
return ArrayRef(TargetFlags);
}
std::optional<RegImmPair>
ARMBaseInstrInfo::isAddImmediate(const MachineInstr &MI, Register Reg) const {
int Sign = 1;
unsigned Opcode = MI.getOpcode();
int64_t Offset = 0;
// TODO: Handle cases where Reg is a super- or sub-register of the
// destination register.
const MachineOperand &Op0 = MI.getOperand(0);
if (!Op0.isReg() || Reg != Op0.getReg())
return std::nullopt;
// We describe SUBri or ADDri instructions.
if (Opcode == ARM::SUBri)
Sign = -1;
else if (Opcode != ARM::ADDri)
return std::nullopt;
// TODO: Third operand can be global address (usually some string). Since
// strings can be relocated we cannot calculate their offsets for
// now.
if (!MI.getOperand(1).isReg() || !MI.getOperand(2).isImm())
return std::nullopt;
Offset = MI.getOperand(2).getImm() * Sign;
return RegImmPair{MI.getOperand(1).getReg(), Offset};
}
bool llvm::registerDefinedBetween(unsigned Reg,
MachineBasicBlock::iterator From,
MachineBasicBlock::iterator To,
const TargetRegisterInfo *TRI) {
for (auto I = From; I != To; ++I)
if (I->modifiesRegister(Reg, TRI))
return true;
return false;
}
MachineInstr *llvm::findCMPToFoldIntoCBZ(MachineInstr *Br,
const TargetRegisterInfo *TRI) {
// Search backwards to the instruction that defines CSPR. This may or not
// be a CMP, we check that after this loop. If we find another instruction
// that reads cpsr, we return nullptr.
MachineBasicBlock::iterator CmpMI = Br;
while (CmpMI != Br->getParent()->begin()) {
--CmpMI;
if (CmpMI->modifiesRegister(ARM::CPSR, TRI))
break;
if (CmpMI->readsRegister(ARM::CPSR, TRI))
break;
}
// Check that this inst is a CMP r[0-7], #0 and that the register
// is not redefined between the cmp and the br.
if (CmpMI->getOpcode() != ARM::tCMPi8 && CmpMI->getOpcode() != ARM::t2CMPri)
return nullptr;
Register Reg = CmpMI->getOperand(0).getReg();
Register PredReg;
ARMCC::CondCodes Pred = getInstrPredicate(*CmpMI, PredReg);
if (Pred != ARMCC::AL || CmpMI->getOperand(1).getImm() != 0)
return nullptr;
if (!isARMLowRegister(Reg))
return nullptr;
if (registerDefinedBetween(Reg, CmpMI->getNextNode(), Br, TRI))
return nullptr;
return &*CmpMI;
}
unsigned llvm::ConstantMaterializationCost(unsigned Val,
const ARMSubtarget *Subtarget,
bool ForCodesize) {
if (Subtarget->isThumb()) {
if (Val <= 255) // MOV
return ForCodesize ? 2 : 1;
if (Subtarget->hasV6T2Ops() && (Val <= 0xffff || // MOV
ARM_AM::getT2SOImmVal(Val) != -1 || // MOVW
ARM_AM::getT2SOImmVal(~Val) != -1)) // MVN
return ForCodesize ? 4 : 1;
if (Val <= 510) // MOV + ADDi8
return ForCodesize ? 4 : 2;
if (~Val <= 255) // MOV + MVN
return ForCodesize ? 4 : 2;
if (ARM_AM::isThumbImmShiftedVal(Val)) // MOV + LSL
return ForCodesize ? 4 : 2;
} else {
if (ARM_AM::getSOImmVal(Val) != -1) // MOV
return ForCodesize ? 4 : 1;
if (ARM_AM::getSOImmVal(~Val) != -1) // MVN
return ForCodesize ? 4 : 1;
if (Subtarget->hasV6T2Ops() && Val <= 0xffff) // MOVW
return ForCodesize ? 4 : 1;
if (ARM_AM::isSOImmTwoPartVal(Val)) // two instrs
return ForCodesize ? 8 : 2;
if (ARM_AM::isSOImmTwoPartValNeg(Val)) // two instrs
return ForCodesize ? 8 : 2;
}
if (Subtarget->useMovt()) // MOVW + MOVT
return ForCodesize ? 8 : 2;
return ForCodesize ? 8 : 3; // Literal pool load
}
bool llvm::HasLowerConstantMaterializationCost(unsigned Val1, unsigned Val2,
const ARMSubtarget *Subtarget,
bool ForCodesize) {
// Check with ForCodesize
unsigned Cost1 = ConstantMaterializationCost(Val1, Subtarget, ForCodesize);
unsigned Cost2 = ConstantMaterializationCost(Val2, Subtarget, ForCodesize);
if (Cost1 < Cost2)
return true;
if (Cost1 > Cost2)
return false;
// If they are equal, try with !ForCodesize
return ConstantMaterializationCost(Val1, Subtarget, !ForCodesize) <
ConstantMaterializationCost(Val2, Subtarget, !ForCodesize);
}
/// Constants defining how certain sequences should be outlined.
/// This encompasses how an outlined function should be called, and what kind of
/// frame should be emitted for that outlined function.
///
/// \p MachineOutlinerTailCall implies that the function is being created from
/// a sequence of instructions ending in a return.
///
/// That is,
///
/// I1 OUTLINED_FUNCTION:
/// I2 --> B OUTLINED_FUNCTION I1
/// BX LR I2
/// BX LR
///
/// +-------------------------+--------+-----+
/// | | Thumb2 | ARM |
/// +-------------------------+--------+-----+
/// | Call overhead in Bytes | 4 | 4 |
/// | Frame overhead in Bytes | 0 | 0 |
/// | Stack fixup required | No | No |
/// +-------------------------+--------+-----+
///
/// \p MachineOutlinerThunk implies that the function is being created from
/// a sequence of instructions ending in a call. The outlined function is
/// called with a BL instruction, and the outlined function tail-calls the
/// original call destination.
///
/// That is,
///
/// I1 OUTLINED_FUNCTION:
/// I2 --> BL OUTLINED_FUNCTION I1
/// BL f I2
/// B f
///
/// +-------------------------+--------+-----+
/// | | Thumb2 | ARM |
/// +-------------------------+--------+-----+
/// | Call overhead in Bytes | 4 | 4 |
/// | Frame overhead in Bytes | 0 | 0 |
/// | Stack fixup required | No | No |
/// +-------------------------+--------+-----+
///
/// \p MachineOutlinerNoLRSave implies that the function should be called using
/// a BL instruction, but doesn't require LR to be saved and restored. This
/// happens when LR is known to be dead.
///
/// That is,
///
/// I1 OUTLINED_FUNCTION:
/// I2 --> BL OUTLINED_FUNCTION I1
/// I3 I2
/// I3
/// BX LR
///
/// +-------------------------+--------+-----+
/// | | Thumb2 | ARM |
/// +-------------------------+--------+-----+
/// | Call overhead in Bytes | 4 | 4 |
/// | Frame overhead in Bytes | 2 | 4 |
/// | Stack fixup required | No | No |
/// +-------------------------+--------+-----+
///
/// \p MachineOutlinerRegSave implies that the function should be called with a
/// save and restore of LR to an available register. This allows us to avoid
/// stack fixups. Note that this outlining variant is compatible with the
/// NoLRSave case.
///
/// That is,
///
/// I1 Save LR OUTLINED_FUNCTION:
/// I2 --> BL OUTLINED_FUNCTION I1
/// I3 Restore LR I2
/// I3
/// BX LR
///
/// +-------------------------+--------+-----+
/// | | Thumb2 | ARM |
/// +-------------------------+--------+-----+
/// | Call overhead in Bytes | 8 | 12 |
/// | Frame overhead in Bytes | 2 | 4 |
/// | Stack fixup required | No | No |
/// +-------------------------+--------+-----+
///
/// \p MachineOutlinerDefault implies that the function should be called with
/// a save and restore of LR to the stack.
///
/// That is,
///
/// I1 Save LR OUTLINED_FUNCTION:
/// I2 --> BL OUTLINED_FUNCTION I1
/// I3 Restore LR I2
/// I3
/// BX LR
///
/// +-------------------------+--------+-----+
/// | | Thumb2 | ARM |
/// +-------------------------+--------+-----+
/// | Call overhead in Bytes | 8 | 12 |
/// | Frame overhead in Bytes | 2 | 4 |
/// | Stack fixup required | Yes | Yes |
/// +-------------------------+--------+-----+
enum MachineOutlinerClass {
MachineOutlinerTailCall,
MachineOutlinerThunk,
MachineOutlinerNoLRSave,
MachineOutlinerRegSave,
MachineOutlinerDefault
};
enum MachineOutlinerMBBFlags {
LRUnavailableSomewhere = 0x2,
HasCalls = 0x4,
UnsafeRegsDead = 0x8
};
struct OutlinerCosts {
int CallTailCall;
int FrameTailCall;
int CallThunk;
int FrameThunk;
int CallNoLRSave;
int FrameNoLRSave;
int CallRegSave;
int FrameRegSave;
int CallDefault;
int FrameDefault;
int SaveRestoreLROnStack;
OutlinerCosts(const ARMSubtarget &target)
: CallTailCall(target.isThumb() ? 4 : 4),
FrameTailCall(target.isThumb() ? 0 : 0),
CallThunk(target.isThumb() ? 4 : 4),
FrameThunk(target.isThumb() ? 0 : 0),
CallNoLRSave(target.isThumb() ? 4 : 4),
FrameNoLRSave(target.isThumb() ? 2 : 4),
CallRegSave(target.isThumb() ? 8 : 12),
FrameRegSave(target.isThumb() ? 2 : 4),
CallDefault(target.isThumb() ? 8 : 12),
FrameDefault(target.isThumb() ? 2 : 4),
SaveRestoreLROnStack(target.isThumb() ? 8 : 8) {}
};
Register
ARMBaseInstrInfo::findRegisterToSaveLRTo(outliner::Candidate &C) const {
MachineFunction *MF = C.getMF();
const TargetRegisterInfo &TRI = *MF->getSubtarget().getRegisterInfo();
const ARMBaseRegisterInfo *ARI =
static_cast<const ARMBaseRegisterInfo *>(&TRI);
BitVector regsReserved = ARI->getReservedRegs(*MF);
// Check if there is an available register across the sequence that we can
// use.
for (Register Reg : ARM::rGPRRegClass) {
if (!(Reg < regsReserved.size() && regsReserved.test(Reg)) &&
Reg != ARM::LR && // LR is not reserved, but don't use it.
Reg != ARM::R12 && // R12 is not guaranteed to be preserved.
C.isAvailableAcrossAndOutOfSeq(Reg, TRI) &&
C.isAvailableInsideSeq(Reg, TRI))
return Reg;
}
return Register();
}
// Compute liveness of LR at the point after the interval [I, E), which
// denotes a *backward* iteration through instructions. Used only for return
// basic blocks, which do not end with a tail call.
static bool isLRAvailable(const TargetRegisterInfo &TRI,
MachineBasicBlock::reverse_iterator I,
MachineBasicBlock::reverse_iterator E) {
// At the end of the function LR dead.
bool Live = false;
for (; I != E; ++I) {
const MachineInstr &MI = *I;
// Check defs of LR.
if (MI.modifiesRegister(ARM::LR, &TRI))
Live = false;
// Check uses of LR.
unsigned Opcode = MI.getOpcode();
if (Opcode == ARM::BX_RET || Opcode == ARM::MOVPCLR ||
Opcode == ARM::SUBS_PC_LR || Opcode == ARM::tBX_RET ||
Opcode == ARM::tBXNS_RET || Opcode == ARM::t2BXAUT_RET) {
// These instructions use LR, but it's not an (explicit or implicit)
// operand.
Live = true;
continue;
}
if (MI.readsRegister(ARM::LR, &TRI))
Live = true;
}
return !Live;
}
/// Return true if \p MI is a call instruction that the outliner can rewrite as
/// a tail call.
static bool CanTransformInstrIntoTailCall(const MachineInstr &MI) {
auto Opcode = MI.getOpcode();
return (Opcode == ARM::BL || Opcode == ARM::BLX || Opcode == ARM::BLX_noip ||
Opcode == ARM::tBL || Opcode == ARM::tBLXi || Opcode == ARM::tBLXr ||
Opcode == ARM::tBLXr_noip);
}
std::optional<std::unique_ptr<outliner::OutlinedFunction>>
ARMBaseInstrInfo::getOutliningCandidateInfo(
const MachineModuleInfo &MMI,
std::vector<outliner::Candidate> &RepeatedSequenceLocs,
unsigned MinRepeats) const {
unsigned SequenceSize = 0;
for (auto &MI : RepeatedSequenceLocs[0])
SequenceSize += getInstSizeInBytes(MI);
// Properties about candidate MBBs that hold for all of them.
unsigned FlagsSetInAll = 0xF;
// Compute liveness information for each candidate, and set FlagsSetInAll.
const TargetRegisterInfo &TRI = getRegisterInfo();
for (outliner::Candidate &C : RepeatedSequenceLocs)
FlagsSetInAll &= C.Flags;
// According to the ARM Procedure Call Standard, the following are
// undefined on entry/exit from a function call:
//
// * Register R12(IP),
// * Condition codes (and thus the CPSR register)
//
// Since we control the instructions which are part of the outlined regions
// we don't need to be fully compliant with the AAPCS, but we have to
// guarantee that if a veneer is inserted at link time the code is still
// correct. Because of this, we can't outline any sequence of instructions
// where one of these registers is live into/across it. Thus, we need to
// delete those candidates.
auto CantGuaranteeValueAcrossCall = [&TRI](outliner::Candidate &C) {
// If the unsafe registers in this block are all dead, then we don't need
// to compute liveness here.
if (C.Flags & UnsafeRegsDead)
return false;
return C.isAnyUnavailableAcrossOrOutOfSeq({ARM::R12, ARM::CPSR}, TRI);
};
// Are there any candidates where those registers are live?
if (!(FlagsSetInAll & UnsafeRegsDead)) {
// Erase every candidate that violates the restrictions above. (It could be
// true that we have viable candidates, so it's not worth bailing out in
// the case that, say, 1 out of 20 candidates violate the restructions.)
llvm::erase_if(RepeatedSequenceLocs, CantGuaranteeValueAcrossCall);
// If the sequence doesn't have enough candidates left, then we're done.
if (RepeatedSequenceLocs.size() < MinRepeats)
return std::nullopt;
}
// We expect the majority of the outlining candidates to be in consensus with
// regard to return address sign and authentication, and branch target
// enforcement, in other words, partitioning according to all the four
// possible combinations of PAC-RET and BTI is going to yield one big subset
// and three small (likely empty) subsets. That allows us to cull incompatible
// candidates separately for PAC-RET and BTI.
// Partition the candidates in two sets: one with BTI enabled and one with BTI
// disabled. Remove the candidates from the smaller set. If they are the same
// number prefer the non-BTI ones for outlining, since they have less
// overhead.
auto NoBTI =
llvm::partition(RepeatedSequenceLocs, [](const outliner::Candidate &C) {
const ARMFunctionInfo &AFI = *C.getMF()->getInfo<ARMFunctionInfo>();
return AFI.branchTargetEnforcement();
});
if (std::distance(RepeatedSequenceLocs.begin(), NoBTI) >
std::distance(NoBTI, RepeatedSequenceLocs.end()))
RepeatedSequenceLocs.erase(NoBTI, RepeatedSequenceLocs.end());
else
RepeatedSequenceLocs.erase(RepeatedSequenceLocs.begin(), NoBTI);
if (RepeatedSequenceLocs.size() < MinRepeats)
return std::nullopt;
// Likewise, partition the candidates according to PAC-RET enablement.
auto NoPAC =
llvm::partition(RepeatedSequenceLocs, [](const outliner::Candidate &C) {
const ARMFunctionInfo &AFI = *C.getMF()->getInfo<ARMFunctionInfo>();
// If the function happens to not spill the LR, do not disqualify it
// from the outlining.
return AFI.shouldSignReturnAddress(true);
});
if (std::distance(RepeatedSequenceLocs.begin(), NoPAC) >
std::distance(NoPAC, RepeatedSequenceLocs.end()))
RepeatedSequenceLocs.erase(NoPAC, RepeatedSequenceLocs.end());
else
RepeatedSequenceLocs.erase(RepeatedSequenceLocs.begin(), NoPAC);
if (RepeatedSequenceLocs.size() < MinRepeats)
return std::nullopt;
// At this point, we have only "safe" candidates to outline. Figure out
// frame + call instruction information.
// Helper lambda which sets call information for every candidate.
auto SetCandidateCallInfo =
[&RepeatedSequenceLocs](unsigned CallID, unsigned NumBytesForCall) {
for (outliner::Candidate &C : RepeatedSequenceLocs)
C.setCallInfo(CallID, NumBytesForCall);
};
OutlinerCosts Costs(Subtarget);
const auto &SomeMFI =
*RepeatedSequenceLocs.front().getMF()->getInfo<ARMFunctionInfo>();
// Adjust costs to account for the BTI instructions.
if (SomeMFI.branchTargetEnforcement()) {
Costs.FrameDefault += 4;
Costs.FrameNoLRSave += 4;
Costs.FrameRegSave += 4;
Costs.FrameTailCall += 4;
Costs.FrameThunk += 4;
}
// Adjust costs to account for sign and authentication instructions.
if (SomeMFI.shouldSignReturnAddress(true)) {
Costs.CallDefault += 8; // +PAC instr, +AUT instr
Costs.SaveRestoreLROnStack += 8; // +PAC instr, +AUT instr
}
unsigned FrameID = MachineOutlinerDefault;
unsigned NumBytesToCreateFrame = Costs.FrameDefault;
// If the last instruction in any candidate is a terminator, then we should
// tail call all of the candidates.
if (RepeatedSequenceLocs[0].back().isTerminator()) {
FrameID = MachineOutlinerTailCall;
NumBytesToCreateFrame = Costs.FrameTailCall;
SetCandidateCallInfo(MachineOutlinerTailCall, Costs.CallTailCall);
} else if (CanTransformInstrIntoTailCall(RepeatedSequenceLocs[0].back())) {
FrameID = MachineOutlinerThunk;
NumBytesToCreateFrame = Costs.FrameThunk;
SetCandidateCallInfo(MachineOutlinerThunk, Costs.CallThunk);
} else {
// We need to decide how to emit calls + frames. We can always emit the same
// frame if we don't need to save to the stack. If we have to save to the
// stack, then we need a different frame.
unsigned NumBytesNoStackCalls = 0;
std::vector<outliner::Candidate> CandidatesWithoutStackFixups;
for (outliner::Candidate &C : RepeatedSequenceLocs) {
// LR liveness is overestimated in return blocks, unless they end with a
// tail call.
const auto Last = C.getMBB()->rbegin();
const bool LRIsAvailable =
C.getMBB()->isReturnBlock() && !Last->isCall()
? isLRAvailable(TRI, Last,
(MachineBasicBlock::reverse_iterator)C.begin())
: C.isAvailableAcrossAndOutOfSeq(ARM::LR, TRI);
if (LRIsAvailable) {
FrameID = MachineOutlinerNoLRSave;
NumBytesNoStackCalls += Costs.CallNoLRSave;
C.setCallInfo(MachineOutlinerNoLRSave, Costs.CallNoLRSave);
CandidatesWithoutStackFixups.push_back(C);
}
// Is an unused register available? If so, we won't modify the stack, so
// we can outline with the same frame type as those that don't save LR.
else if (findRegisterToSaveLRTo(C)) {
FrameID = MachineOutlinerRegSave;
NumBytesNoStackCalls += Costs.CallRegSave;
C.setCallInfo(MachineOutlinerRegSave, Costs.CallRegSave);
CandidatesWithoutStackFixups.push_back(C);
}
// Is SP used in the sequence at all? If not, we don't have to modify
// the stack, so we are guaranteed to get the same frame.
else if (C.isAvailableInsideSeq(ARM::SP, TRI)) {
NumBytesNoStackCalls += Costs.CallDefault;
C.setCallInfo(MachineOutlinerDefault, Costs.CallDefault);
CandidatesWithoutStackFixups.push_back(C);
}
// If we outline this, we need to modify the stack. Pretend we don't
// outline this by saving all of its bytes.
else
NumBytesNoStackCalls += SequenceSize;
}
// If there are no places where we have to save LR, then note that we don't
// have to update the stack. Otherwise, give every candidate the default
// call type
if (NumBytesNoStackCalls <=
RepeatedSequenceLocs.size() * Costs.CallDefault) {
RepeatedSequenceLocs = CandidatesWithoutStackFixups;
FrameID = MachineOutlinerNoLRSave;
if (RepeatedSequenceLocs.size() < MinRepeats)
return std::nullopt;
} else
SetCandidateCallInfo(MachineOutlinerDefault, Costs.CallDefault);
}
// Does every candidate's MBB contain a call? If so, then we might have a
// call in the range.
if (FlagsSetInAll & MachineOutlinerMBBFlags::HasCalls) {
// check if the range contains a call. These require a save + restore of
// the link register.
outliner::Candidate &FirstCand = RepeatedSequenceLocs[0];
if (any_of(drop_end(FirstCand),
[](const MachineInstr &MI) { return MI.isCall(); }))
NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
// Handle the last instruction separately. If it is tail call, then the
// last instruction is a call, we don't want to save + restore in this
// case. However, it could be possible that the last instruction is a
// call without it being valid to tail call this sequence. We should
// consider this as well.
else if (FrameID != MachineOutlinerThunk &&
FrameID != MachineOutlinerTailCall && FirstCand.back().isCall())
NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
}
return std::make_unique<outliner::OutlinedFunction>(
RepeatedSequenceLocs, SequenceSize, NumBytesToCreateFrame, FrameID);
}
bool ARMBaseInstrInfo::checkAndUpdateStackOffset(MachineInstr *MI,
int64_t Fixup,
bool Updt) const {
int SPIdx = MI->findRegisterUseOperandIdx(ARM::SP, /*TRI=*/nullptr);
unsigned AddrMode = (MI->getDesc().TSFlags & ARMII::AddrModeMask);
if (SPIdx < 0)
// No SP operand
return true;
else if (SPIdx != 1 && (AddrMode != ARMII::AddrModeT2_i8s4 || SPIdx != 2))
// If SP is not the base register we can't do much
return false;
// Stack might be involved but addressing mode doesn't handle any offset.
// Rq: AddrModeT1_[1|2|4] don't operate on SP
if (AddrMode == ARMII::AddrMode1 || // Arithmetic instructions
AddrMode == ARMII::AddrMode4 || // Load/Store Multiple
AddrMode == ARMII::AddrMode6 || // Neon Load/Store Multiple
AddrMode == ARMII::AddrModeT2_so || // SP can't be used as based register
AddrMode == ARMII::AddrModeT2_pc || // PCrel access
AddrMode == ARMII::AddrMode2 || // Used by PRE and POST indexed LD/ST
AddrMode == ARMII::AddrModeT2_i7 || // v8.1-M MVE
AddrMode == ARMII::AddrModeT2_i7s2 || // v8.1-M MVE
AddrMode == ARMII::AddrModeT2_i7s4 || // v8.1-M sys regs VLDR/VSTR
AddrMode == ARMII::AddrModeNone ||
AddrMode == ARMII::AddrModeT2_i8 || // Pre/Post inc instructions
AddrMode == ARMII::AddrModeT2_i8neg) // Always negative imm
return false;
unsigned NumOps = MI->getDesc().getNumOperands();
unsigned ImmIdx = NumOps - 3;
const MachineOperand &Offset = MI->getOperand(ImmIdx);
assert(Offset.isImm() && "Is not an immediate");
int64_t OffVal = Offset.getImm();
if (OffVal < 0)
// Don't override data if the are below SP.
return false;
unsigned NumBits = 0;
unsigned Scale = 1;
switch (AddrMode) {
case ARMII::AddrMode3:
if (ARM_AM::getAM3Op(OffVal) == ARM_AM::sub)
return false;
OffVal = ARM_AM::getAM3Offset(OffVal);
NumBits = 8;
break;
case ARMII::AddrMode5:
if (ARM_AM::getAM5Op(OffVal) == ARM_AM::sub)
return false;
OffVal = ARM_AM::getAM5Offset(OffVal);
NumBits = 8;
Scale = 4;
break;
case ARMII::AddrMode5FP16:
if (ARM_AM::getAM5FP16Op(OffVal) == ARM_AM::sub)
return false;
OffVal = ARM_AM::getAM5FP16Offset(OffVal);
NumBits = 8;
Scale = 2;
break;
case ARMII::AddrModeT2_i8pos:
NumBits = 8;
break;
case ARMII::AddrModeT2_i8s4:
// FIXME: Values are already scaled in this addressing mode.
assert((Fixup & 3) == 0 && "Can't encode this offset!");
NumBits = 10;
break;
case ARMII::AddrModeT2_ldrex:
NumBits = 8;
Scale = 4;
break;
case ARMII::AddrModeT2_i12:
case ARMII::AddrMode_i12:
NumBits = 12;
break;
case ARMII::AddrModeT1_s: // SP-relative LD/ST
NumBits = 8;
Scale = 4;
break;
default:
llvm_unreachable("Unsupported addressing mode!");
}
// Make sure the offset is encodable for instructions that scale the
// immediate.
assert(((OffVal * Scale + Fixup) & (Scale - 1)) == 0 &&
"Can't encode this offset!");
OffVal += Fixup / Scale;
unsigned Mask = (1 << NumBits) - 1;
if (OffVal <= Mask) {
if (Updt)
MI->getOperand(ImmIdx).setImm(OffVal);
return true;
}
return false;
}
void ARMBaseInstrInfo::mergeOutliningCandidateAttributes(
Function &F, std::vector<outliner::Candidate> &Candidates) const {
outliner::Candidate &C = Candidates.front();
// branch-target-enforcement is guaranteed to be consistent between all
// candidates, so we only need to look at one.
const Function &CFn = C.getMF()->getFunction();
if (CFn.hasFnAttribute("branch-target-enforcement"))
F.addFnAttr(CFn.getFnAttribute("branch-target-enforcement"));
if (CFn.hasFnAttribute("sign-return-address"))
F.addFnAttr(CFn.getFnAttribute("sign-return-address"));
ARMGenInstrInfo::mergeOutliningCandidateAttributes(F, Candidates);
}
bool ARMBaseInstrInfo::isFunctionSafeToOutlineFrom(
MachineFunction &MF, bool OutlineFromLinkOnceODRs) const {
const Function &F = MF.getFunction();
// Can F be deduplicated by the linker? If it can, don't outline from it.
if (!OutlineFromLinkOnceODRs && F.hasLinkOnceODRLinkage())
return false;
// Don't outline from functions with section markings; the program could
// expect that all the code is in the named section.
// FIXME: Allow outlining from multiple functions with the same section
// marking.
if (F.hasSection())
return false;
// FIXME: Thumb1 outlining is not handled
if (MF.getInfo<ARMFunctionInfo>()->isThumb1OnlyFunction())
return false;
// It's safe to outline from MF.
return true;
}
bool ARMBaseInstrInfo::isMBBSafeToOutlineFrom(MachineBasicBlock &MBB,
unsigned &Flags) const {
// Check if LR is available through all of the MBB. If it's not, then set
// a flag.
assert(MBB.getParent()->getRegInfo().tracksLiveness() &&
"Suitable Machine Function for outlining must track liveness");
LiveRegUnits LRU(getRegisterInfo());
for (MachineInstr &MI : llvm::reverse(MBB))
LRU.accumulate(MI);
// Check if each of the unsafe registers are available...
bool R12AvailableInBlock = LRU.available(ARM::R12);
bool CPSRAvailableInBlock = LRU.available(ARM::CPSR);
// If all of these are dead (and not live out), we know we don't have to check
// them later.
if (R12AvailableInBlock && CPSRAvailableInBlock)
Flags |= MachineOutlinerMBBFlags::UnsafeRegsDead;
// Now, add the live outs to the set.
LRU.addLiveOuts(MBB);
// If any of these registers is available in the MBB, but also a live out of
// the block, then we know outlining is unsafe.
if (R12AvailableInBlock && !LRU.available(ARM::R12))
return false;
if (CPSRAvailableInBlock && !LRU.available(ARM::CPSR))
return false;
// Check if there's a call inside this MachineBasicBlock. If there is, then
// set a flag.
if (any_of(MBB, [](MachineInstr &MI) { return MI.isCall(); }))
Flags |= MachineOutlinerMBBFlags::HasCalls;
// LR liveness is overestimated in return blocks.
bool LRIsAvailable =
MBB.isReturnBlock() && !MBB.back().isCall()
? isLRAvailable(getRegisterInfo(), MBB.rbegin(), MBB.rend())
: LRU.available(ARM::LR);
if (!LRIsAvailable)
Flags |= MachineOutlinerMBBFlags::LRUnavailableSomewhere;
return true;
}
outliner::InstrType
ARMBaseInstrInfo::getOutliningTypeImpl(const MachineModuleInfo &MMI,
MachineBasicBlock::iterator &MIT,
unsigned Flags) const {
MachineInstr &MI = *MIT;
const TargetRegisterInfo *TRI = &getRegisterInfo();
// PIC instructions contain labels, outlining them would break offset
// computing. unsigned Opc = MI.getOpcode();
unsigned Opc = MI.getOpcode();
if (Opc == ARM::tPICADD || Opc == ARM::PICADD || Opc == ARM::PICSTR ||
Opc == ARM::PICSTRB || Opc == ARM::PICSTRH || Opc == ARM::PICLDR ||
Opc == ARM::PICLDRB || Opc == ARM::PICLDRH || Opc == ARM::PICLDRSB ||
Opc == ARM::PICLDRSH || Opc == ARM::t2LDRpci_pic ||
Opc == ARM::t2MOVi16_ga_pcrel || Opc == ARM::t2MOVTi16_ga_pcrel ||
Opc == ARM::t2MOV_ga_pcrel)
return outliner::InstrType::Illegal;
// Be conservative with ARMv8.1 MVE instructions.
if (Opc == ARM::t2BF_LabelPseudo || Opc == ARM::t2DoLoopStart ||
Opc == ARM::t2DoLoopStartTP || Opc == ARM::t2WhileLoopStart ||
Opc == ARM::t2WhileLoopStartLR || Opc == ARM::t2WhileLoopStartTP ||
Opc == ARM::t2LoopDec || Opc == ARM::t2LoopEnd ||
Opc == ARM::t2LoopEndDec)
return outliner::InstrType::Illegal;
const MCInstrDesc &MCID = MI.getDesc();
uint64_t MIFlags = MCID.TSFlags;
if ((MIFlags & ARMII::DomainMask) == ARMII::DomainMVE)
return outliner::InstrType::Illegal;
// Is this a terminator for a basic block?
if (MI.isTerminator())
// TargetInstrInfo::getOutliningType has already filtered out anything
// that would break this, so we can allow it here.
return outliner::InstrType::Legal;
// Don't outline if link register or program counter value are used.
if (MI.readsRegister(ARM::LR, TRI) || MI.readsRegister(ARM::PC, TRI))
return outliner::InstrType::Illegal;
if (MI.isCall()) {
// Get the function associated with the call. Look at each operand and find
// the one that represents the calle and get its name.
const Function *Callee = nullptr;
for (const MachineOperand &MOP : MI.operands()) {
if (MOP.isGlobal()) {
Callee = dyn_cast<Function>(MOP.getGlobal());
break;
}
}
// Dont't outline calls to "mcount" like functions, in particular Linux
// kernel function tracing relies on it.
if (Callee &&
(Callee->getName() == "\01__gnu_mcount_nc" ||
Callee->getName() == "\01mcount" || Callee->getName() == "__mcount"))
return outliner::InstrType::Illegal;
// If we don't know anything about the callee, assume it depends on the
// stack layout of the caller. In that case, it's only legal to outline
// as a tail-call. Explicitly list the call instructions we know about so
// we don't get unexpected results with call pseudo-instructions.
auto UnknownCallOutlineType = outliner::InstrType::Illegal;
if (CanTransformInstrIntoTailCall(MI))
UnknownCallOutlineType = outliner::InstrType::LegalTerminator;
if (!Callee)
return UnknownCallOutlineType;
// We have a function we have information about. Check if it's something we
// can safely outline.
MachineFunction *CalleeMF = MMI.getMachineFunction(*Callee);
// We don't know what's going on with the callee at all. Don't touch it.
if (!CalleeMF)
return UnknownCallOutlineType;
// Check if we know anything about the callee saves on the function. If we
// don't, then don't touch it, since that implies that we haven't computed
// anything about its stack frame yet.
MachineFrameInfo &MFI = CalleeMF->getFrameInfo();
if (!MFI.isCalleeSavedInfoValid() || MFI.getStackSize() > 0 ||
MFI.getNumObjects() > 0)
return UnknownCallOutlineType;
// At this point, we can say that CalleeMF ought to not pass anything on the
// stack. Therefore, we can outline it.
return outliner::InstrType::Legal;
}
// Since calls are handled, don't touch LR or PC
if (MI.modifiesRegister(ARM::LR, TRI) || MI.modifiesRegister(ARM::PC, TRI))
return outliner::InstrType::Illegal;
// Does this use the stack?
if (MI.modifiesRegister(ARM::SP, TRI) || MI.readsRegister(ARM::SP, TRI)) {
// True if there is no chance that any outlined candidate from this range
// could require stack fixups. That is, both
// * LR is available in the range (No save/restore around call)
// * The range doesn't include calls (No save/restore in outlined frame)
// are true.
// These conditions also ensure correctness of the return address
// authentication - we insert sign and authentication instructions only if
// we save/restore LR on stack, but then this condition ensures that the
// outlined range does not modify the SP, therefore the SP value used for
// signing is the same as the one used for authentication.
// FIXME: This is very restrictive; the flags check the whole block,
// not just the bit we will try to outline.
bool MightNeedStackFixUp =
(Flags & (MachineOutlinerMBBFlags::LRUnavailableSomewhere |
MachineOutlinerMBBFlags::HasCalls));
if (!MightNeedStackFixUp)
return outliner::InstrType::Legal;
// Any modification of SP will break our code to save/restore LR.
// FIXME: We could handle some instructions which add a constant offset to
// SP, with a bit more work.
if (MI.modifiesRegister(ARM::SP, TRI))
return outliner::InstrType::Illegal;
// At this point, we have a stack instruction that we might need to fix up.
// up. We'll handle it if it's a load or store.
if (checkAndUpdateStackOffset(&MI, Subtarget.getStackAlignment().value(),
false))
return outliner::InstrType::Legal;
// We can't fix it up, so don't outline it.
return outliner::InstrType::Illegal;
}
// Be conservative with IT blocks.
if (MI.readsRegister(ARM::ITSTATE, TRI) ||
MI.modifiesRegister(ARM::ITSTATE, TRI))
return outliner::InstrType::Illegal;
// Don't outline CFI instructions.
if (MI.isCFIInstruction())
return outliner::InstrType::Illegal;
return outliner::InstrType::Legal;
}
void ARMBaseInstrInfo::fixupPostOutline(MachineBasicBlock &MBB) const {
for (MachineInstr &MI : MBB) {
checkAndUpdateStackOffset(&MI, Subtarget.getStackAlignment().value(), true);
}
}
void ARMBaseInstrInfo::saveLROnStack(MachineBasicBlock &MBB,
MachineBasicBlock::iterator It, bool CFI,
bool Auth) const {
int Align = std::max(Subtarget.getStackAlignment().value(), uint64_t(8));
unsigned MIFlags = CFI ? MachineInstr::FrameSetup : 0;
assert(Align >= 8 && Align <= 256);
if (Auth) {
assert(Subtarget.isThumb2());
// Compute PAC in R12. Outlining ensures R12 is dead across the outlined
// sequence.
BuildMI(MBB, It, DebugLoc(), get(ARM::t2PAC)).setMIFlags(MIFlags);
BuildMI(MBB, It, DebugLoc(), get(ARM::t2STRD_PRE), ARM::SP)
.addReg(ARM::R12, RegState::Kill)
.addReg(ARM::LR, RegState::Kill)
.addReg(ARM::SP)
.addImm(-Align)
.add(predOps(ARMCC::AL))
.setMIFlags(MIFlags);
} else {
unsigned Opc = Subtarget.isThumb() ? ARM::t2STR_PRE : ARM::STR_PRE_IMM;
BuildMI(MBB, It, DebugLoc(), get(Opc), ARM::SP)
.addReg(ARM::LR, RegState::Kill)
.addReg(ARM::SP)
.addImm(-Align)
.add(predOps(ARMCC::AL))
.setMIFlags(MIFlags);
}
if (!CFI)
return;
// Add a CFI, saying CFA is offset by Align bytes from SP.
CFIInstBuilder CFIBuilder(MBB, It, MachineInstr::FrameSetup);
CFIBuilder.buildDefCFAOffset(Align);
// Add a CFI saying that the LR that we want to find is now higher than
// before.
int LROffset = Auth ? Align - 4 : Align;
CFIBuilder.buildOffset(ARM::LR, -LROffset);
if (Auth) {
// Add a CFI for the location of the return address PAC.
CFIBuilder.buildOffset(ARM::RA_AUTH_CODE, -Align);
}
}
void ARMBaseInstrInfo::restoreLRFromStack(MachineBasicBlock &MBB,
MachineBasicBlock::iterator It,
bool CFI, bool Auth) const {
int Align = Subtarget.getStackAlignment().value();
unsigned MIFlags = CFI ? MachineInstr::FrameDestroy : 0;
if (Auth) {
assert(Subtarget.isThumb2());
// Restore return address PAC and LR.
BuildMI(MBB, It, DebugLoc(), get(ARM::t2LDRD_POST))
.addReg(ARM::R12, RegState::Define)
.addReg(ARM::LR, RegState::Define)
.addReg(ARM::SP, RegState::Define)
.addReg(ARM::SP)
.addImm(Align)
.add(predOps(ARMCC::AL))
.setMIFlags(MIFlags);
// LR authentication is after the CFI instructions, below.
} else {
unsigned Opc = Subtarget.isThumb() ? ARM::t2LDR_POST : ARM::LDR_POST_IMM;
MachineInstrBuilder MIB = BuildMI(MBB, It, DebugLoc(), get(Opc), ARM::LR)
.addReg(ARM::SP, RegState::Define)
.addReg(ARM::SP);
if (!Subtarget.isThumb())
MIB.addReg(0);
MIB.addImm(Subtarget.getStackAlignment().value())
.add(predOps(ARMCC::AL))
.setMIFlags(MIFlags);
}
if (CFI) {
// Now stack has moved back up and we have restored LR.
CFIInstBuilder CFIBuilder(MBB, It, MachineInstr::FrameDestroy);
CFIBuilder.buildDefCFAOffset(0);
CFIBuilder.buildRestore(ARM::LR);
if (Auth)
CFIBuilder.buildUndefined(ARM::RA_AUTH_CODE);
}
if (Auth)
BuildMI(MBB, It, DebugLoc(), get(ARM::t2AUT));
}
void ARMBaseInstrInfo::buildOutlinedFrame(
MachineBasicBlock &MBB, MachineFunction &MF,
const outliner::OutlinedFunction &OF) const {
// For thunk outlining, rewrite the last instruction from a call to a
// tail-call.
if (OF.FrameConstructionID == MachineOutlinerThunk) {
MachineInstr *Call = &*--MBB.instr_end();
bool isThumb = Subtarget.isThumb();
unsigned FuncOp = isThumb ? 2 : 0;
unsigned Opc = Call->getOperand(FuncOp).isReg()
? isThumb ? ARM::tTAILJMPr : ARM::TAILJMPr
: isThumb ? Subtarget.isTargetMachO() ? ARM::tTAILJMPd
: ARM::tTAILJMPdND
: ARM::TAILJMPd;
MachineInstrBuilder MIB = BuildMI(MBB, MBB.end(), DebugLoc(), get(Opc))
.add(Call->getOperand(FuncOp));
if (isThumb && !Call->getOperand(FuncOp).isReg())
MIB.add(predOps(ARMCC::AL));
Call->eraseFromParent();
}
// Is there a call in the outlined range?
auto IsNonTailCall = [](MachineInstr &MI) {
return MI.isCall() && !MI.isReturn();
};
if (llvm::any_of(MBB.instrs(), IsNonTailCall)) {
MachineBasicBlock::iterator It = MBB.begin();
MachineBasicBlock::iterator Et = MBB.end();
if (OF.FrameConstructionID == MachineOutlinerTailCall ||
OF.FrameConstructionID == MachineOutlinerThunk)
Et = std::prev(MBB.end());
// We have to save and restore LR, we need to add it to the liveins if it
// is not already part of the set. This is sufficient since outlined
// functions only have one block.
if (!MBB.isLiveIn(ARM::LR))
MBB.addLiveIn(ARM::LR);
// Insert a save before the outlined region
bool Auth = MF.getInfo<ARMFunctionInfo>()->shouldSignReturnAddress(true);
saveLROnStack(MBB, It, true, Auth);
// Fix up the instructions in the range, since we're going to modify the
// stack.
assert(OF.FrameConstructionID != MachineOutlinerDefault &&
"Can only fix up stack references once");
fixupPostOutline(MBB);
// Insert a restore before the terminator for the function. Restore LR.
restoreLRFromStack(MBB, Et, true, Auth);
}
// If this is a tail call outlined function, then there's already a return.
if (OF.FrameConstructionID == MachineOutlinerTailCall ||
OF.FrameConstructionID == MachineOutlinerThunk)
return;
// Here we have to insert the return ourselves. Get the correct opcode from
// current feature set.
BuildMI(MBB, MBB.end(), DebugLoc(), get(Subtarget.getReturnOpcode()))
.add(predOps(ARMCC::AL));
// Did we have to modify the stack by saving the link register?
if (OF.FrameConstructionID != MachineOutlinerDefault &&
OF.Candidates[0].CallConstructionID != MachineOutlinerDefault)
return;
// We modified the stack.
// Walk over the basic block and fix up all the stack accesses.
fixupPostOutline(MBB);
}
MachineBasicBlock::iterator ARMBaseInstrInfo::insertOutlinedCall(
Module &M, MachineBasicBlock &MBB, MachineBasicBlock::iterator &It,
MachineFunction &MF, outliner::Candidate &C) const {
MachineInstrBuilder MIB;
MachineBasicBlock::iterator CallPt;
unsigned Opc;
bool isThumb = Subtarget.isThumb();
// Are we tail calling?
if (C.CallConstructionID == MachineOutlinerTailCall) {
// If yes, then we can just branch to the label.
Opc = isThumb
? Subtarget.isTargetMachO() ? ARM::tTAILJMPd : ARM::tTAILJMPdND
: ARM::TAILJMPd;
MIB = BuildMI(MF, DebugLoc(), get(Opc))
.addGlobalAddress(M.getNamedValue(MF.getName()));
if (isThumb)
MIB.add(predOps(ARMCC::AL));
It = MBB.insert(It, MIB);
return It;
}
// Create the call instruction.
Opc = isThumb ? ARM::tBL : ARM::BL;
MachineInstrBuilder CallMIB = BuildMI(MF, DebugLoc(), get(Opc));
if (isThumb)
CallMIB.add(predOps(ARMCC::AL));
CallMIB.addGlobalAddress(M.getNamedValue(MF.getName()));
if (C.CallConstructionID == MachineOutlinerNoLRSave ||
C.CallConstructionID == MachineOutlinerThunk) {
// No, so just insert the call.
It = MBB.insert(It, CallMIB);
return It;
}
const ARMFunctionInfo &AFI = *C.getMF()->getInfo<ARMFunctionInfo>();
// Can we save to a register?
if (C.CallConstructionID == MachineOutlinerRegSave) {
Register Reg = findRegisterToSaveLRTo(C);
assert(Reg != 0 && "No callee-saved register available?");
// Save and restore LR from that register.
copyPhysReg(MBB, It, DebugLoc(), Reg, ARM::LR, true);
if (!AFI.isLRSpilled())
CFIInstBuilder(MBB, It, MachineInstr::FrameSetup)
.buildRegister(ARM::LR, Reg);
CallPt = MBB.insert(It, CallMIB);
copyPhysReg(MBB, It, DebugLoc(), ARM::LR, Reg, true);
if (!AFI.isLRSpilled())
CFIInstBuilder(MBB, It, MachineInstr::FrameDestroy).buildRestore(ARM::LR);
It--;
return CallPt;
}
// We have the default case. Save and restore from SP.
if (!MBB.isLiveIn(ARM::LR))
MBB.addLiveIn(ARM::LR);
bool Auth = !AFI.isLRSpilled() && AFI.shouldSignReturnAddress(true);
saveLROnStack(MBB, It, !AFI.isLRSpilled(), Auth);
CallPt = MBB.insert(It, CallMIB);
restoreLRFromStack(MBB, It, !AFI.isLRSpilled(), Auth);
It--;
return CallPt;
}
bool ARMBaseInstrInfo::shouldOutlineFromFunctionByDefault(
MachineFunction &MF) const {
return Subtarget.isMClass() && MF.getFunction().hasMinSize();
}
bool ARMBaseInstrInfo::isReMaterializableImpl(
const MachineInstr &MI) const {
// Try hard to rematerialize any VCTPs because if we spill P0, it will block
// the tail predication conversion. This means that the element count
// register has to be live for longer, but that has to be better than
// spill/restore and VPT predication.
return (isVCTP(&MI) && !isPredicated(MI)) ||
TargetInstrInfo::isReMaterializableImpl(MI);
}
unsigned llvm::getBLXOpcode(const MachineFunction &MF) {
return (MF.getSubtarget<ARMSubtarget>().hardenSlsBlr()) ? ARM::BLX_noip
: ARM::BLX;
}
unsigned llvm::gettBLXrOpcode(const MachineFunction &MF) {
return (MF.getSubtarget<ARMSubtarget>().hardenSlsBlr()) ? ARM::tBLXr_noip
: ARM::tBLXr;
}
unsigned llvm::getBLXpredOpcode(const MachineFunction &MF) {
return (MF.getSubtarget<ARMSubtarget>().hardenSlsBlr()) ? ARM::BLX_pred_noip
: ARM::BLX_pred;
}
namespace {
class ARMPipelinerLoopInfo : public TargetInstrInfo::PipelinerLoopInfo {
MachineInstr *EndLoop, *LoopCount;
MachineFunction *MF;
const TargetInstrInfo *TII;
// Bitset[0 .. MAX_STAGES-1] ... iterations needed
// [LAST_IS_USE] : last reference to register in schedule is a use
// [SEEN_AS_LIVE] : Normal pressure algorithm believes register is live
static int constexpr MAX_STAGES = 30;
static int constexpr LAST_IS_USE = MAX_STAGES;
static int constexpr SEEN_AS_LIVE = MAX_STAGES + 1;
typedef std::bitset<MAX_STAGES + 2> IterNeed;
typedef std::map<Register, IterNeed> IterNeeds;
void bumpCrossIterationPressure(RegPressureTracker &RPT,
const IterNeeds &CIN);
bool tooMuchRegisterPressure(SwingSchedulerDAG &SSD, SMSchedule &SMS);
// Meanings of the various stuff with loop types:
// t2Bcc:
// EndLoop = branch at end of original BB that will become a kernel
// LoopCount = CC setter live into branch
// t2LoopEnd:
// EndLoop = branch at end of original BB
// LoopCount = t2LoopDec
public:
ARMPipelinerLoopInfo(MachineInstr *EndLoop, MachineInstr *LoopCount)
: EndLoop(EndLoop), LoopCount(LoopCount),
MF(EndLoop->getParent()->getParent()),
TII(MF->getSubtarget().getInstrInfo()) {}
bool shouldIgnoreForPipelining(const MachineInstr *MI) const override {
// Only ignore the terminator.
return MI == EndLoop || MI == LoopCount;
}
bool shouldUseSchedule(SwingSchedulerDAG &SSD, SMSchedule &SMS) override {
if (tooMuchRegisterPressure(SSD, SMS))
return false;
return true;
}
std::optional<bool> createTripCountGreaterCondition(
int TC, MachineBasicBlock &MBB,
SmallVectorImpl<MachineOperand> &Cond) override {
if (isCondBranchOpcode(EndLoop->getOpcode())) {
Cond.push_back(EndLoop->getOperand(1));
Cond.push_back(EndLoop->getOperand(2));
if (EndLoop->getOperand(0).getMBB() == EndLoop->getParent()) {
TII->reverseBranchCondition(Cond);
}
return {};
} else if (EndLoop->getOpcode() == ARM::t2LoopEnd) {
// General case just lets the unrolled t2LoopDec do the subtraction and
// therefore just needs to check if zero has been reached.
MachineInstr *LoopDec = nullptr;
for (auto &I : MBB.instrs())
if (I.getOpcode() == ARM::t2LoopDec)
LoopDec = &I;
assert(LoopDec && "Unable to find copied LoopDec");
// Check if we're done with the loop.
BuildMI(&MBB, LoopDec->getDebugLoc(), TII->get(ARM::t2CMPri))
.addReg(LoopDec->getOperand(0).getReg())
.addImm(0)
.addImm(ARMCC::AL)
.addReg(Register());
Cond.push_back(MachineOperand::CreateImm(ARMCC::EQ));
Cond.push_back(MachineOperand::CreateReg(ARM::CPSR, false));
return {};
} else
llvm_unreachable("Unknown EndLoop");
}
void setPreheader(MachineBasicBlock *NewPreheader) override {}
void adjustTripCount(int TripCountAdjust) override {}
};
void ARMPipelinerLoopInfo::bumpCrossIterationPressure(RegPressureTracker &RPT,
const IterNeeds &CIN) {
// Increase pressure by the amounts in CrossIterationNeeds
for (const auto &N : CIN) {
int Cnt = N.second.count() - N.second[SEEN_AS_LIVE] * 2;
for (int I = 0; I < Cnt; ++I)
RPT.increaseRegPressure(VirtRegOrUnit(N.first), LaneBitmask::getNone(),
LaneBitmask::getAll());
}
// Decrease pressure by the amounts in CrossIterationNeeds
for (const auto &N : CIN) {
int Cnt = N.second.count() - N.second[SEEN_AS_LIVE] * 2;
for (int I = 0; I < Cnt; ++I)
RPT.decreaseRegPressure(VirtRegOrUnit(N.first), LaneBitmask::getAll(),
LaneBitmask::getNone());
}
}
bool ARMPipelinerLoopInfo::tooMuchRegisterPressure(SwingSchedulerDAG &SSD,
SMSchedule &SMS) {
IterNeeds CrossIterationNeeds;
// Determine which values will be loop-carried after the schedule is
// applied
for (auto &SU : SSD.SUnits) {
const MachineInstr *MI = SU.getInstr();
int Stg = SMS.stageScheduled(const_cast<SUnit *>(&SU));
for (auto &S : SU.Succs)
if (MI->isPHI() && S.getKind() == SDep::Anti) {
Register Reg = S.getReg();
if (Reg.isVirtual())
CrossIterationNeeds[Reg.id()].set(0);
} else if (S.isAssignedRegDep()) {
int OStg = SMS.stageScheduled(S.getSUnit());
if (OStg >= 0 && OStg != Stg) {
Register Reg = S.getReg();
if (Reg.isVirtual())
CrossIterationNeeds[Reg.id()] |= ((1 << (OStg - Stg)) - 1);
}
}
}
// Determine more-or-less what the proposed schedule (reversed) is going to
// be; it might not be quite the same because the within-cycle ordering
// created by SMSchedule depends upon changes to help with address offsets and
// the like.
std::vector<SUnit *> ProposedSchedule;
for (int Cycle = SMS.getFinalCycle(); Cycle >= SMS.getFirstCycle(); --Cycle)
for (int Stage = 0, StageEnd = SMS.getMaxStageCount(); Stage <= StageEnd;
++Stage) {
std::deque<SUnit *> Instrs =
SMS.getInstructions(Cycle + Stage * SMS.getInitiationInterval());
std::sort(Instrs.begin(), Instrs.end(),
[](SUnit *A, SUnit *B) { return A->NodeNum > B->NodeNum; });
llvm::append_range(ProposedSchedule, Instrs);
}
// Learn whether the last use/def of each cross-iteration register is a use or
// def. If it is a def, RegisterPressure will implicitly increase max pressure
// and we do not have to add the pressure.
for (auto *SU : ProposedSchedule)
for (ConstMIBundleOperands OperI(*SU->getInstr()); OperI.isValid();
++OperI) {
auto MO = *OperI;
if (!MO.isReg() || !MO.getReg())
continue;
Register Reg = MO.getReg();
auto CIter = CrossIterationNeeds.find(Reg.id());
if (CIter == CrossIterationNeeds.end() || CIter->second[LAST_IS_USE] ||
CIter->second[SEEN_AS_LIVE])
continue;
if (MO.isDef() && !MO.isDead())
CIter->second.set(SEEN_AS_LIVE);
else if (MO.isUse())
CIter->second.set(LAST_IS_USE);
}
for (auto &CI : CrossIterationNeeds)
CI.second.reset(LAST_IS_USE);
RegionPressure RecRegPressure;
RegPressureTracker RPTracker(RecRegPressure);
RegisterClassInfo RegClassInfo;
RegClassInfo.runOnMachineFunction(*MF);
RPTracker.init(MF, &RegClassInfo, nullptr, EndLoop->getParent(),
EndLoop->getParent()->end(), false, false);
bumpCrossIterationPressure(RPTracker, CrossIterationNeeds);
for (auto *SU : ProposedSchedule) {
MachineBasicBlock::const_iterator CurInstI = SU->getInstr();
RPTracker.setPos(std::next(CurInstI));
RPTracker.recede();
// Track what cross-iteration registers would be seen as live
for (ConstMIBundleOperands OperI(*CurInstI); OperI.isValid(); ++OperI) {
auto MO = *OperI;
if (!MO.isReg() || !MO.getReg())
continue;
Register Reg = MO.getReg();
if (MO.isDef() && !MO.isDead()) {
auto CIter = CrossIterationNeeds.find(Reg.id());
if (CIter != CrossIterationNeeds.end()) {
CIter->second.reset(0);
CIter->second.reset(SEEN_AS_LIVE);
}
}
}
for (auto &S : SU->Preds) {
auto Stg = SMS.stageScheduled(SU);
if (S.isAssignedRegDep()) {
Register Reg = S.getReg();
auto CIter = CrossIterationNeeds.find(Reg.id());
if (CIter != CrossIterationNeeds.end()) {
auto Stg2 = SMS.stageScheduled(S.getSUnit());
assert(Stg2 <= Stg && "Data dependence upon earlier stage");
if (Stg - Stg2 < MAX_STAGES)
CIter->second.set(Stg - Stg2);
CIter->second.set(SEEN_AS_LIVE);
}
}
}
bumpCrossIterationPressure(RPTracker, CrossIterationNeeds);
}
auto &P = RPTracker.getPressure().MaxSetPressure;
for (unsigned I = 0, E = P.size(); I < E; ++I) {
// Exclude some Neon register classes.
if (I == ARM::DQuad_with_ssub_0 || I == ARM::DTripleSpc_with_ssub_0 ||
I == ARM::DTriple_with_qsub_0_in_QPR)
continue;
if (P[I] > RegClassInfo.getRegPressureSetLimit(I)) {
return true;
}
}
return false;
}
} // namespace
std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
ARMBaseInstrInfo::analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const {
MachineBasicBlock::iterator I = LoopBB->getFirstTerminator();
MachineBasicBlock *Preheader = *LoopBB->pred_begin();
if (Preheader == LoopBB)
Preheader = *std::next(LoopBB->pred_begin());
if (I != LoopBB->end() && I->getOpcode() == ARM::t2Bcc) {
// If the branch is a Bcc, then the CPSR should be set somewhere within the
// block. We need to determine the reaching definition of CPSR so that
// it can be marked as non-pipelineable, allowing the pipeliner to force
// it into stage 0 or give up if it cannot or will not do so.
MachineInstr *CCSetter = nullptr;
for (auto &L : LoopBB->instrs()) {
if (L.isCall())
return nullptr;
if (isCPSRDefined(L))
CCSetter = &L;
}
if (CCSetter)
return std::make_unique<ARMPipelinerLoopInfo>(&*I, CCSetter);
else
return nullptr; // Unable to find the CC setter, so unable to guarantee
// that pipeline will work
}
// Recognize:
// preheader:
// %1 = t2DoopLoopStart %0
// loop:
// %2 = phi %1, <not loop>, %..., %loop
// %3 = t2LoopDec %2, <imm>
// t2LoopEnd %3, %loop
if (I != LoopBB->end() && I->getOpcode() == ARM::t2LoopEnd) {
for (auto &L : LoopBB->instrs())
if (L.isCall())
return nullptr;
else if (isVCTP(&L))
return nullptr;
Register LoopDecResult = I->getOperand(0).getReg();
MachineRegisterInfo &MRI = LoopBB->getParent()->getRegInfo();
MachineInstr *LoopDec = MRI.getUniqueVRegDef(LoopDecResult);
if (!LoopDec || LoopDec->getOpcode() != ARM::t2LoopDec)
return nullptr;
MachineInstr *LoopStart = nullptr;
for (auto &J : Preheader->instrs())
if (J.getOpcode() == ARM::t2DoLoopStart)
LoopStart = &J;
if (!LoopStart)
return nullptr;
return std::make_unique<ARMPipelinerLoopInfo>(&*I, LoopDec);
}
return nullptr;
}