#include "ARMBaseRegisterInfo.h"
#include "ARMMachineFunctionInfo.h"
#include "MCTargetDesc/ARMAddressingModes.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
using namespace llvm;
STATISTIC(NumLDMGened , "Number of ldm instructions generated");
RegScavenger *RS;
bool isThumb2;
- virtual bool runOnMachineFunction(MachineFunction &Fn);
+ bool runOnMachineFunction(MachineFunction &Fn) override;
- virtual const char *getPassName() const {
+ const char *getPassName() const override {
return "ARM load / store optimization pass";
}
typedef SmallVector<MemOpQueueEntry,8> MemOpQueue;
typedef MemOpQueue::iterator MemOpQueueIter;
+ void findUsesOfImpDef(SmallVectorImpl<MachineOperand *> &UsesOfImpDefs,
+ const MemOpQueue &MemOps, unsigned DefReg,
+ unsigned RangeBegin, unsigned RangeEnd);
+
bool MergeOps(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
int Offset, unsigned Base, bool BaseKill, int Opcode,
ARMCC::CondCodes Pred, unsigned PredReg, unsigned Scratch,
unsigned PredReg,
unsigned Scratch,
DebugLoc dl,
- SmallVector<MachineBasicBlock::iterator, 4> &Merges);
+ SmallVectorImpl<MachineBasicBlock::iterator> &Merges);
void MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, unsigned Base,
int Opcode, unsigned Size,
ARMCC::CondCodes Pred, unsigned PredReg,
unsigned Scratch, MemOpQueue &MemOps,
- SmallVector<MachineBasicBlock::iterator, 4> &Merges);
+ SmallVectorImpl<MachineBasicBlock::iterator> &Merges);
void AdvanceRS(MachineBasicBlock &MBB, MemOpQueue &MemOps);
bool FixInvalidRegPairOp(MachineBasicBlock &MBB,
return true;
}
+/// \brief Find all instructions using a given imp-def within a range.
+///
+/// We are trying to combine a range of instructions, one of which (located at
+/// position RangeBegin) implicitly defines a register. The final LDM/STM will
+/// be placed at RangeEnd, and so any uses of this definition between RangeStart
+/// and RangeEnd must be modified to use an undefined value.
+///
+/// The live range continues until we find a second definition or one of the
+/// uses we find is a kill. Unfortunately MemOps is not sorted by Position, so
+/// we must consider all uses and decide which are relevant in a second pass.
+void ARMLoadStoreOpt::findUsesOfImpDef(
+ SmallVectorImpl<MachineOperand *> &UsesOfImpDefs, const MemOpQueue &MemOps,
+ unsigned DefReg, unsigned RangeBegin, unsigned RangeEnd) {
+ std::map<unsigned, MachineOperand *> Uses;
+ unsigned LastLivePos = RangeEnd;
+
+ // First we find all uses of this register with Position between RangeBegin
+ // and RangeEnd, any or all of these could be uses of a definition at
+ // RangeBegin. We also record the latest position a definition at RangeBegin
+ // would be considered live.
+ for (unsigned i = 0; i < MemOps.size(); ++i) {
+ MachineInstr &MI = *MemOps[i].MBBI;
+ unsigned MIPosition = MemOps[i].Position;
+ if (MIPosition <= RangeBegin || MIPosition > RangeEnd)
+ continue;
+
+ // If this instruction defines the register, then any later use will be of
+ // that definition rather than ours.
+ if (MI.definesRegister(DefReg))
+ LastLivePos = std::min(LastLivePos, MIPosition);
+
+ MachineOperand *UseOp = MI.findRegisterUseOperand(DefReg);
+ if (!UseOp)
+ continue;
+
+ // If this instruction kills the register then (assuming liveness is
+ // correct when we start) we don't need to think about anything after here.
+ if (UseOp->isKill())
+ LastLivePos = std::min(LastLivePos, MIPosition);
+
+ Uses[MIPosition] = UseOp;
+ }
+
+ // Now we traverse the list of all uses, and append the ones that actually use
+ // our definition to the requested list.
+ for (std::map<unsigned, MachineOperand *>::iterator I = Uses.begin(),
+ E = Uses.end();
+ I != E; ++I) {
+ // List is sorted by position so once we've found one out of range there
+ // will be no more to consider.
+ if (I->first > LastLivePos)
+ break;
+ UsesOfImpDefs.push_back(I->second);
+ }
+}
+
// MergeOpsUpdate - call MergeOps and update MemOps and merges accordingly on
// success.
void ARMLoadStoreOpt::MergeOpsUpdate(MachineBasicBlock &MBB,
ARMCC::CondCodes Pred, unsigned PredReg,
unsigned Scratch,
DebugLoc dl,
- SmallVector<MachineBasicBlock::iterator, 4> &Merges) {
+ SmallVectorImpl<MachineBasicBlock::iterator> &Merges) {
// First calculate which of the registers should be killed by the merged
// instruction.
const unsigned insertPos = memOps[insertAfter].Position;
SmallVector<std::pair<unsigned, bool>, 8> Regs;
SmallVector<unsigned, 8> ImpDefs;
+ SmallVector<MachineOperand *, 8> UsesOfImpDefs;
for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) {
unsigned Reg = memOps[i].Reg;
// If we are inserting the merged operation after an operation that
unsigned DefReg = MO->getReg();
if (std::find(ImpDefs.begin(), ImpDefs.end(), DefReg) == ImpDefs.end())
ImpDefs.push_back(DefReg);
+
+ // There may be other uses of the definition between this instruction and
+ // the eventual LDM/STM position. These should be marked undef if the
+ // merge takes place.
+ findUsesOfImpDef(UsesOfImpDefs, memOps, DefReg, memOps[i].Position,
+ insertPos);
}
}
return;
// Merge succeeded, update records.
- Merges.push_back(prior(Loc));
+ Merges.push_back(std::prev(Loc));
+
+ // In gathering loads together, we may have moved the imp-def of a register
+ // past one of its uses. This is OK, since we know better than the rest of
+ // LLVM what's OK with ARM loads and stores; but we still have to adjust the
+ // affected uses.
+ for (SmallVectorImpl<MachineOperand *>::iterator I = UsesOfImpDefs.begin(),
+ E = UsesOfImpDefs.end();
+ I != E; ++I)
+ (*I)->setIsUndef();
+
for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) {
// Remove kill flags from any memops that come before insertPos.
if (Regs[i-memOpsBegin].second) {
/// load / store multiple instructions.
void
ARMLoadStoreOpt::MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex,
- unsigned Base, int Opcode, unsigned Size,
- ARMCC::CondCodes Pred, unsigned PredReg,
- unsigned Scratch, MemOpQueue &MemOps,
- SmallVector<MachineBasicBlock::iterator, 4> &Merges) {
+ unsigned Base, int Opcode, unsigned Size,
+ ARMCC::CondCodes Pred, unsigned PredReg,
+ unsigned Scratch, MemOpQueue &MemOps,
+ SmallVectorImpl<MachineBasicBlock::iterator> &Merges) {
bool isNotVFP = isi32Load(Opcode) || isi32Store(Opcode);
int Offset = MemOps[SIndex].Offset;
int SOffset = Offset;
DebugLoc dl = Loc->getDebugLoc();
const MachineOperand &PMO = Loc->getOperand(0);
unsigned PReg = PMO.getReg();
- unsigned PRegNum = PMO.isUndef() ? UINT_MAX
- : getARMRegisterNumbering(PReg);
+ unsigned PRegNum = PMO.isUndef() ? UINT_MAX : TRI->getEncodingValue(PReg);
unsigned Count = 1;
unsigned Limit = ~0U;
int NewOffset = MemOps[i].Offset;
const MachineOperand &MO = MemOps[i].MBBI->getOperand(0);
unsigned Reg = MO.getReg();
- unsigned RegNum = MO.isUndef() ? UINT_MAX
- : getARMRegisterNumbering(Reg);
+ unsigned RegNum = MO.isUndef() ? UINT_MAX : TRI->getEncodingValue(Reg);
// Register numbers must be in ascending order. For VFP / NEON load and
// store multiples, the registers must also be consecutive and within the
// limit on the number of registers per instruction.
if (Reg != ARM::SP &&
NewOffset == Offset + (int)Size &&
((isNotVFP && RegNum > PRegNum) ||
- ((Count < Limit) && RegNum == PRegNum+1))) {
+ ((Count < Limit) && RegNum == PRegNum+1)) &&
+ // On Swift we don't want vldm/vstm to start with a odd register num
+ // because Q register unaligned vldm/vstm need more uops.
+ (!STI->isSwift() || isNotVFP || Count != 1 || !(PRegNum & 0x1))) {
Offset += Size;
PRegNum = RegNum;
++Count;
// Try merging with the previous instruction.
MachineBasicBlock::iterator BeginMBBI = MBB.begin();
if (MBBI != BeginMBBI) {
- MachineBasicBlock::iterator PrevMBBI = prior(MBBI);
+ MachineBasicBlock::iterator PrevMBBI = std::prev(MBBI);
while (PrevMBBI != BeginMBBI && PrevMBBI->isDebugValue())
--PrevMBBI;
if (Mode == ARM_AM::ia &&
// Try merging with the next instruction.
MachineBasicBlock::iterator EndMBBI = MBB.end();
if (!DoMerge && MBBI != EndMBBI) {
- MachineBasicBlock::iterator NextMBBI = llvm::next(MBBI);
+ MachineBasicBlock::iterator NextMBBI = std::next(MBBI);
while (NextMBBI != EndMBBI && NextMBBI->isDebugValue())
++NextMBBI;
if ((Mode == ARM_AM::ia || Mode == ARM_AM::ib) &&
bool isLd = isi32Load(Opcode) || Opcode == ARM::VLDRS || Opcode == ARM::VLDRD;
// Can't do the merge if the destination register is the same as the would-be
// writeback register.
- if (isLd && MI->getOperand(0).getReg() == Base)
+ if (MI->getOperand(0).getReg() == Base)
return false;
unsigned PredReg = 0;
// Try merging with the previous instruction.
MachineBasicBlock::iterator BeginMBBI = MBB.begin();
if (MBBI != BeginMBBI) {
- MachineBasicBlock::iterator PrevMBBI = prior(MBBI);
+ MachineBasicBlock::iterator PrevMBBI = std::prev(MBBI);
while (PrevMBBI != BeginMBBI && PrevMBBI->isDebugValue())
--PrevMBBI;
if (isMatchingDecrement(PrevMBBI, Base, Bytes, Limit, Pred, PredReg)) {
// Try merging with the next instruction.
MachineBasicBlock::iterator EndMBBI = MBB.end();
if (!DoMerge && MBBI != EndMBBI) {
- MachineBasicBlock::iterator NextMBBI = llvm::next(MBBI);
+ MachineBasicBlock::iterator NextMBBI = std::next(MBBI);
while (NextMBBI != EndMBBI && NextMBBI->isDebugValue())
++NextMBBI;
if (!isAM5 &&
}
if (Loc != MBB.begin())
- RS->forward(prior(Loc));
+ RS->forward(std::prev(Loc));
}
static int getMemoryOpOffset(const MachineInstr *MI) {
getKillRegState(OddDeadKill) | getUndefRegState(OddUndef));
++NumSTRD2STM;
}
- NewBBI = llvm::prior(MBBI);
+ NewBBI = std::prev(MBBI);
} else {
// Split into two instructions.
unsigned NewOpc = (isLd)
? (isT2 ? (OffImm < 0 ? ARM::t2LDRi8 : ARM::t2LDRi12) : ARM::LDRi12)
: (isT2 ? (OffImm < 0 ? ARM::t2STRi8 : ARM::t2STRi12) : ARM::STRi12);
+ // Be extra careful for thumb2. t2LDRi8 can't reference a zero offset,
+ // so adjust and use t2LDRi12 here for that.
+ unsigned NewOpc2 = (isLd)
+ ? (isT2 ? (OffImm+4 < 0 ? ARM::t2LDRi8 : ARM::t2LDRi12) : ARM::LDRi12)
+ : (isT2 ? (OffImm+4 < 0 ? ARM::t2STRi8 : ARM::t2STRi12) : ARM::STRi12);
DebugLoc dl = MBBI->getDebugLoc();
// If this is a load and base register is killed, it may have been
// re-defed by the load, make sure the first load does not clobber it.
(BaseKill || OffKill) &&
(TRI->regsOverlap(EvenReg, BaseReg))) {
assert(!TRI->regsOverlap(OddReg, BaseReg));
- InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc,
+ InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc2,
OddReg, OddDeadKill, false,
BaseReg, false, BaseUndef, false, OffUndef,
Pred, PredReg, TII, isT2);
- NewBBI = llvm::prior(MBBI);
+ NewBBI = std::prev(MBBI);
InsertLDR_STR(MBB, MBBI, OffImm, isLd, dl, NewOpc,
EvenReg, EvenDeadKill, false,
BaseReg, BaseKill, BaseUndef, OffKill, OffUndef,
EvenDeadKill = false;
OddDeadKill = true;
}
+ // Never kill the base register in the first instruction.
+ if (EvenReg == BaseReg)
+ EvenDeadKill = false;
InsertLDR_STR(MBB, MBBI, OffImm, isLd, dl, NewOpc,
EvenReg, EvenDeadKill, EvenUndef,
BaseReg, false, BaseUndef, false, OffUndef,
Pred, PredReg, TII, isT2);
- NewBBI = llvm::prior(MBBI);
- InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc,
+ NewBBI = std::prev(MBBI);
+ InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc2,
OddReg, OddDeadKill, OddUndef,
BaseReg, BaseKill, BaseUndef, OffKill, OffUndef,
Pred, PredReg, TII, isT2);
// merge the ldr's so far, including this one. But don't try to
// combine the following ldr(s).
Clobber = (isi32Load(Opcode) && Base == MBBI->getOperand(0).getReg());
+
+ // Watch out for:
+ // r4 := ldr [r0, #8]
+ // r4 := ldr [r0, #4]
+ //
+ // The optimization may reorder the second ldr in front of the first
+ // ldr, which violates write after write(WAW) dependence. The same as
+ // str. Try to merge inst(s) already in MemOps.
+ bool Overlap = false;
+ for (MemOpQueueIter I = MemOps.begin(), E = MemOps.end(); I != E; ++I) {
+ if (TRI->regsOverlap(Reg, I->MBBI->getOperand(0).getReg())) {
+ Overlap = true;
+ break;
+ }
+ }
+
if (CurrBase == 0 && !Clobber) {
// Start of a new chain.
CurrBase = Base;
MemOps.push_back(MemOpQueueEntry(Offset, Reg, isKill, Position, MBBI));
++NumMemOps;
Advance = true;
- } else {
+ } else if (!Overlap) {
if (Clobber) {
TryMerge = true;
Advance = true;
// First advance to the instruction just before the start of the chain.
AdvanceRS(MBB, MemOps);
// Find a scratch register.
- unsigned Scratch = RS->FindUnusedReg(ARM::GPRRegisterClass);
+ unsigned Scratch = RS->FindUnusedReg(&ARM::GPRRegClass);
// Process the load / store instructions.
- RS->forward(prior(MBBI));
+ RS->forward(std::prev(MBBI));
// Merge ops.
Merges.clear();
++NumMerges;
// RS may be pointing to an instruction that's deleted.
- RS->skipTo(prior(MBBI));
+ RS->skipTo(std::prev(MBBI));
} else if (NumMemOps == 1) {
// Try folding preceding/trailing base inc/dec into the single
// load/store.
if (MergeBaseUpdateLoadStore(MBB, MemOps[0].MBBI, TII, Advance, MBBI)) {
++NumMerges;
- RS->forward(prior(MBBI));
+ RS->forward(std::prev(MBBI));
}
}
(MBBI->getOpcode() == ARM::BX_RET ||
MBBI->getOpcode() == ARM::tBX_RET ||
MBBI->getOpcode() == ARM::MOVPCLR)) {
- MachineInstr *PrevMI = prior(MBBI);
+ MachineInstr *PrevMI = std::prev(MBBI);
unsigned Opcode = PrevMI->getOpcode();
if (Opcode == ARM::LDMIA_UPD || Opcode == ARM::LDMDA_UPD ||
Opcode == ARM::LDMDB_UPD || Opcode == ARM::LDMIB_UPD ||
Opcode == ARM::LDMIA_UPD) && "Unsupported multiple load-return!");
PrevMI->setDesc(TII->get(NewOpc));
MO.setReg(ARM::PC);
- PrevMI->copyImplicitOps(&*MBBI);
+ PrevMI->copyImplicitOps(*MBB.getParent(), &*MBBI);
MBB.erase(MBBI);
return true;
}
static char ID;
ARMPreAllocLoadStoreOpt() : MachineFunctionPass(ID) {}
- const TargetData *TD;
+ const DataLayout *TD;
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
const ARMSubtarget *STI;
MachineRegisterInfo *MRI;
MachineFunction *MF;
- virtual bool runOnMachineFunction(MachineFunction &Fn);
+ bool runOnMachineFunction(MachineFunction &Fn) override;
- virtual const char *getPassName() const {
+ const char *getPassName() const override {
return "ARM pre- register allocation load / store optimization pass";
}
unsigned &PredReg, ARMCC::CondCodes &Pred,
bool &isT2);
bool RescheduleOps(MachineBasicBlock *MBB,
- SmallVector<MachineInstr*, 4> &Ops,
+ SmallVectorImpl<MachineInstr *> &Ops,
unsigned Base, bool isLd,
DenseMap<MachineInstr*, unsigned> &MI2LocMap);
bool RescheduleLoadStoreInstrs(MachineBasicBlock *MBB);
}
bool ARMPreAllocLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) {
- TD = Fn.getTarget().getTargetData();
+ TD = Fn.getTarget().getDataLayout();
TII = Fn.getTarget().getInstrInfo();
TRI = Fn.getTarget().getRegisterInfo();
STI = &Fn.getTarget().getSubtarget<ARMSubtarget>();
return false;
// Make sure the base address satisfies i64 ld / st alignment requirement.
+ // At the moment, we ignore the memoryoperand's value.
+ // If we want to use AliasAnalysis, we should check it accordingly.
if (!Op0->hasOneMemOperand() ||
- !(*Op0->memoperands_begin())->getValue() ||
(*Op0->memoperands_begin())->isVolatile())
return false;
return true;
}
-namespace {
- struct OffsetCompare {
- bool operator()(const MachineInstr *LHS, const MachineInstr *RHS) const {
- int LOffset = getMemoryOpOffset(LHS);
- int ROffset = getMemoryOpOffset(RHS);
- assert(LHS == RHS || LOffset != ROffset);
- return LOffset > ROffset;
- }
- };
-}
-
bool ARMPreAllocLoadStoreOpt::RescheduleOps(MachineBasicBlock *MBB,
- SmallVector<MachineInstr*, 4> &Ops,
+ SmallVectorImpl<MachineInstr *> &Ops,
unsigned Base, bool isLd,
DenseMap<MachineInstr*, unsigned> &MI2LocMap) {
bool RetVal = false;
// Sort by offset (in reverse order).
- std::sort(Ops.begin(), Ops.end(), OffsetCompare());
+ std::sort(Ops.begin(), Ops.end(),
+ [](const MachineInstr *LHS, const MachineInstr *RHS) {
+ int LOffset = getMemoryOpOffset(LHS);
+ int ROffset = getMemoryOpOffset(RHS);
+ assert(LHS == RHS || LOffset != ROffset);
+ return LOffset > ROffset;
+ });
// The loads / stores of the same base are in order. Scan them from first to
// last and check for the following:
Ops.pop_back();
const MCInstrDesc &MCID = TII->get(NewOpc);
- const TargetRegisterClass *TRC = TII->getRegClass(MCID, 0, TRI);
+ const TargetRegisterClass *TRC = TII->getRegClass(MCID, 0, TRI, *MF);
MRI->constrainRegClass(EvenReg, TRC);
MRI->constrainRegClass(OddReg, TRC);
if (!StopHere)
BI->second.push_back(MI);
} else {
- SmallVector<MachineInstr*, 4> MIs;
- MIs.push_back(MI);
- Base2LdsMap[Base] = MIs;
+ Base2LdsMap[Base].push_back(MI);
LdBases.push_back(Base);
}
} else {
if (!StopHere)
BI->second.push_back(MI);
} else {
- SmallVector<MachineInstr*, 4> MIs;
- MIs.push_back(MI);
- Base2StsMap[Base] = MIs;
+ Base2StsMap[Base].push_back(MI);
StBases.push_back(Base);
}
}
// Re-schedule loads.
for (unsigned i = 0, e = LdBases.size(); i != e; ++i) {
unsigned Base = LdBases[i];
- SmallVector<MachineInstr*, 4> &Lds = Base2LdsMap[Base];
+ SmallVectorImpl<MachineInstr *> &Lds = Base2LdsMap[Base];
if (Lds.size() > 1)
RetVal |= RescheduleOps(MBB, Lds, Base, true, MI2LocMap);
}
// Re-schedule stores.
for (unsigned i = 0, e = StBases.size(); i != e; ++i) {
unsigned Base = StBases[i];
- SmallVector<MachineInstr*, 4> &Sts = Base2StsMap[Base];
+ SmallVectorImpl<MachineInstr *> &Sts = Base2StsMap[Base];
if (Sts.size() > 1)
RetVal |= RescheduleOps(MBB, Sts, Base, false, MI2LocMap);
}