/// memory instruction can be moved to a delay slot.
class MemDefsUses : public InspectMemInstr {
public:
- MemDefsUses(const MachineFrameInfo *MFI);
+ MemDefsUses(const DataLayout &DL, const MachineFrameInfo *MFI);
private:
typedef PointerUnion<const Value *, const PseudoSourceValue *> ValueType;
const MachineFrameInfo *MFI;
SmallPtrSet<ValueType, 4> Uses, Defs;
+ const DataLayout &DL;
/// Flags indicating whether loads or stores with no underlying objects have
/// been seen.
Iter replaceWithCompactBranch(MachineBasicBlock &MBB,
Iter Branch, DebugLoc DL);
+ Iter replaceWithCompactJump(MachineBasicBlock &MBB,
+ Iter Jump, DebugLoc DL);
+
/// This function checks if it is valid to move Candidate to the delay slot
/// and returns true if it isn't. It also updates memory and register
/// dependence information.
/// moved to the delay slot. Returns true on success.
template<typename IterTy>
bool searchRange(MachineBasicBlock &MBB, IterTy Begin, IterTy End,
- RegDefsUses &RegDU, InspectMemInstr &IM,
- IterTy &Filler, Iter Slot) const;
+ RegDefsUses &RegDU, InspectMemInstr &IM, Iter Slot,
+ IterTy &Filler) const;
/// This function searches in the backward direction for an instruction that
/// can be moved to the delay slot. Returns true on success.
void RegDefsUses::setCallerSaved(const MachineInstr &MI) {
assert(MI.isCall());
+ // Add RA/RA_64 to Defs to prevent users of RA/RA_64 from going into
+ // the delay slot. The reason is that RA/RA_64 must not be changed
+ // in the delay slot so that the callee can return to the caller.
+ if (MI.definesRegister(Mips::RA) || MI.definesRegister(Mips::RA_64)) {
+ Defs.set(Mips::RA);
+ Defs.set(Mips::RA_64);
+ }
+
// If MI is a call, add all caller-saved registers to Defs.
BitVector CallerSavedRegs(TRI.getNumRegs(), true);
CallerSavedRegs.reset(Mips::ZERO);
CallerSavedRegs.reset(Mips::ZERO_64);
- for (const MCPhysReg *R = TRI.getCalleeSavedRegs(); *R; ++R)
+ for (const MCPhysReg *R = TRI.getCalleeSavedRegs(MI.getParent()->getParent());
+ *R; ++R)
for (MCRegAliasIterator AI(*R, &TRI, true); AI.isValid(); ++AI)
CallerSavedRegs.reset(*AI);
for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
SE = MBB.succ_end(); SI != SE; ++SI)
if (*SI != &SuccBB)
- for (MachineBasicBlock::livein_iterator LI = (*SI)->livein_begin(),
- LE = (*SI)->livein_end(); LI != LE; ++LI)
- Uses.set(*LI);
+ for (const auto &LI : (*SI)->liveins())
+ Uses.set(LI.PhysReg);
}
bool RegDefsUses::update(const MachineInstr &MI, unsigned Begin, unsigned End) {
(*MI.memoperands_begin())->getPseudoValue()) {
if (isa<FixedStackPseudoSourceValue>(PSV))
return false;
- return !PSV->isConstant(nullptr) && PSV != PseudoSourceValue::getStack();
+ return !PSV->isConstant(nullptr) && !PSV->isStack();
}
return true;
}
-MemDefsUses::MemDefsUses(const MachineFrameInfo *MFI_)
- : InspectMemInstr(false), MFI(MFI_), SeenNoObjLoad(false),
- SeenNoObjStore(false) {}
+MemDefsUses::MemDefsUses(const DataLayout &DL, const MachineFrameInfo *MFI_)
+ : InspectMemInstr(false), MFI(MFI_), DL(DL), SeenNoObjLoad(false),
+ SeenNoObjStore(false) {}
bool MemDefsUses::hasHazard_(const MachineInstr &MI) {
bool HasHazard = false;
const Value *V = (*MI.memoperands_begin())->getValue();
SmallVector<Value *, 4> Objs;
- GetUnderlyingObjects(const_cast<Value *>(V), Objs);
+ GetUnderlyingObjects(const_cast<Value *>(V), Objs, DL);
for (SmallVectorImpl<Value *>::iterator I = Objs.begin(), E = Objs.end();
I != E; ++I) {
// Replace Branch with the compact branch instruction.
Iter Filler::replaceWithCompactBranch(MachineBasicBlock &MBB,
Iter Branch, DebugLoc DL) {
- const MipsInstrInfo *TII = static_cast<const MipsInstrInfo *>(
- MBB.getParent()->getSubtarget().getInstrInfo());
+ const MipsInstrInfo *TII =
+ MBB.getParent()->getSubtarget<MipsSubtarget>().getInstrInfo();
unsigned NewOpcode =
(((unsigned) Branch->getOpcode()) == Mips::BEQ) ? Mips::BEQZC_MM
return Branch;
}
+// Replace Jumps with the compact jump instruction.
+Iter Filler::replaceWithCompactJump(MachineBasicBlock &MBB,
+ Iter Jump, DebugLoc DL) {
+ const MipsInstrInfo *TII =
+ MBB.getParent()->getSubtarget<MipsSubtarget>().getInstrInfo();
+
+ const MCInstrDesc &NewDesc = TII->get(Mips::JRC16_MM);
+ MachineInstrBuilder MIB = BuildMI(MBB, Jump, DL, NewDesc);
+
+ MIB.addReg(Jump->getOperand(0).getReg());
+
+ Iter tmpIter = Jump;
+ Jump = std::prev(Jump);
+ MBB.erase(tmpIter);
+
+ return Jump;
+}
+
// For given opcode returns opcode of corresponding instruction with short
// delay slot.
static int getEquivalentCallShort(int Opcode) {
/// We assume there is only one delay slot per delayed instruction.
bool Filler::runOnMachineBasicBlock(MachineBasicBlock &MBB) {
bool Changed = false;
- const MipsSubtarget &STI =
- static_cast<const MipsSubtarget &>(MBB.getParent()->getSubtarget());
+ const MipsSubtarget &STI = MBB.getParent()->getSubtarget<MipsSubtarget>();
bool InMicroMipsMode = STI.inMicroMipsMode();
const MipsInstrInfo *TII = STI.getInstrInfo();
// Get instruction with delay slot.
MachineBasicBlock::instr_iterator DSI(I);
- if (InMicroMipsMode && TII->GetInstSizeInBytes(std::next(DSI)) == 2 &&
+ if (InMicroMipsMode && TII->GetInstSizeInBytes(&*std::next(DSI)) == 2 &&
DSI->isCall()) {
// If instruction in delay slot is 16b change opcode to
// corresponding instruction with short delay slot.
// adding NOP replace this instruction with the corresponding compact
// branch instruction, i.e. BEQZC or BNEZC.
unsigned Opcode = I->getOpcode();
- if (InMicroMipsMode &&
- (Opcode == Mips::BEQ || Opcode == Mips::BNE) &&
- ((unsigned) I->getOperand(1).getReg()) == Mips::ZERO) {
-
- I = replaceWithCompactBranch(MBB, I, I->getDebugLoc());
-
- } else {
- // Bundle the NOP to the instruction with the delay slot.
- BuildMI(MBB, std::next(I), I->getDebugLoc(), TII->get(Mips::NOP));
- MIBundleBuilder(MBB, I, std::next(I, 2));
+ if (InMicroMipsMode) {
+ switch (Opcode) {
+ case Mips::BEQ:
+ case Mips::BNE:
+ if (((unsigned) I->getOperand(1).getReg()) == Mips::ZERO) {
+ I = replaceWithCompactBranch(MBB, I, I->getDebugLoc());
+ continue;
+ }
+ break;
+ case Mips::JR:
+ case Mips::PseudoReturn:
+ case Mips::PseudoIndirectBranch:
+ // For microMIPS the PseudoReturn and PseudoIndirectBranch are allways
+ // expanded to JR_MM, so they can be replaced with JRC16_MM.
+ I = replaceWithCompactJump(MBB, I, I->getDebugLoc());
+ continue;
+ default:
+ break;
+ }
}
+ // Bundle the NOP to the instruction with the delay slot.
+ BuildMI(MBB, std::next(I), I->getDebugLoc(), TII->get(Mips::NOP));
+ MIBundleBuilder(MBB, I, std::next(I, 2));
}
return Changed;
template<typename IterTy>
bool Filler::searchRange(MachineBasicBlock &MBB, IterTy Begin, IterTy End,
- RegDefsUses &RegDU, InspectMemInstr& IM,
- IterTy &Filler, Iter Slot) const {
- for (IterTy I = Begin; I != End; ++I) {
+ RegDefsUses &RegDU, InspectMemInstr& IM, Iter Slot,
+ IterTy &Filler) const {
+ bool IsReverseIter = std::is_convertible<IterTy, ReverseIter>::value;
+
+ for (IterTy I = Begin; I != End;) {
+ IterTy CurrI = I;
+ ++I;
+
// skip debug value
- if (I->isDebugValue())
+ if (CurrI->isDebugValue())
continue;
- if (terminateSearch(*I))
+ if (terminateSearch(*CurrI))
break;
- assert((!I->isCall() && !I->isReturn() && !I->isBranch()) &&
+ assert((!CurrI->isCall() && !CurrI->isReturn() && !CurrI->isBranch()) &&
"Cannot put calls, returns or branches in delay slot.");
- if (delayHasHazard(*I, RegDU, IM))
+ if (CurrI->isKill()) {
+ CurrI->eraseFromParent();
+
+ // This special case is needed for reverse iterators, because when we
+ // erase an instruction, the iterators are updated to point to the next
+ // instruction.
+ if (IsReverseIter && I != End)
+ I = CurrI;
+ continue;
+ }
+
+ if (delayHasHazard(*CurrI, RegDU, IM))
continue;
- if (static_cast<const MipsSubtarget &>(MBB.getParent()->getSubtarget())
- .isTargetNaCl()) {
+ const MipsSubtarget &STI = MBB.getParent()->getSubtarget<MipsSubtarget>();
+ if (STI.isTargetNaCl()) {
// In NaCl, instructions that must be masked are forbidden in delay slots.
// We only check for loads, stores and SP changes. Calls, returns and
// branches are not checked because non-NaCl targets never put them in
// delay slots.
unsigned AddrIdx;
- if ((isBasePlusOffsetMemoryAccess(I->getOpcode(), &AddrIdx) &&
- baseRegNeedsLoadStoreMask(I->getOperand(AddrIdx).getReg())) ||
- I->modifiesRegister(Mips::SP,
- TM.getSubtargetImpl()->getRegisterInfo()))
+ if ((isBasePlusOffsetMemoryAccess(CurrI->getOpcode(), &AddrIdx) &&
+ baseRegNeedsLoadStoreMask(CurrI->getOperand(AddrIdx).getReg())) ||
+ CurrI->modifiesRegister(Mips::SP, STI.getRegisterInfo()))
continue;
}
- bool InMicroMipsMode = TM.getSubtarget<MipsSubtarget>().inMicroMipsMode();
- const MipsInstrInfo *TII = static_cast<const MipsInstrInfo *>(
- TM.getSubtargetImpl()->getInstrInfo());
+ bool InMicroMipsMode = STI.inMicroMipsMode();
+ const MipsInstrInfo *TII = STI.getInstrInfo();
unsigned Opcode = (*Slot).getOpcode();
- if (InMicroMipsMode && TII->GetInstSizeInBytes(&(*I)) == 2 &&
+ if (InMicroMipsMode && TII->GetInstSizeInBytes(&(*CurrI)) == 2 &&
(Opcode == Mips::JR || Opcode == Mips::PseudoIndirectBranch ||
Opcode == Mips::PseudoReturn))
continue;
- Filler = I;
+ Filler = CurrI;
return true;
}
if (DisableBackwardSearch)
return false;
- RegDefsUses RegDU(*MBB.getParent()->getSubtarget().getRegisterInfo());
- MemDefsUses MemDU(MBB.getParent()->getFrameInfo());
+ auto *Fn = MBB.getParent();
+ RegDefsUses RegDU(*Fn->getSubtarget().getRegisterInfo());
+ MemDefsUses MemDU(Fn->getDataLayout(), Fn->getFrameInfo());
ReverseIter Filler;
RegDU.init(*Slot);
- if (!searchRange(MBB, ReverseIter(Slot), MBB.rend(), RegDU, MemDU, Filler,
- Slot))
+ if (!searchRange(MBB, ReverseIter(Slot), MBB.rend(), RegDU, MemDU, Slot,
+ Filler))
return false;
MBB.splice(std::next(Slot), &MBB, std::next(Filler).base());
RegDU.setCallerSaved(*Slot);
- if (!searchRange(MBB, std::next(Slot), MBB.end(), RegDU, NM, Filler, Slot))
+ if (!searchRange(MBB, std::next(Slot), MBB.end(), RegDU, NM, Slot, Filler))
return false;
MBB.splice(std::next(Slot), &MBB, Filler);
BB2BrMap BrMap;
std::unique_ptr<InspectMemInstr> IM;
Iter Filler;
+ auto *Fn = MBB.getParent();
// Iterate over SuccBB's predecessor list.
for (MachineBasicBlock::pred_iterator PI = SuccBB->pred_begin(),
// Do not allow moving instructions which have unallocatable register operands
// across basic block boundaries.
- RegDU.setUnallocatableRegs(*MBB.getParent());
+ RegDU.setUnallocatableRegs(*Fn);
// Only allow moving loads from stack or constants if any of the SuccBB's
// predecessors have multiple successors.
if (HasMultipleSuccs) {
IM.reset(new LoadFromStackOrConst());
} else {
- const MachineFrameInfo *MFI = MBB.getParent()->getFrameInfo();
- IM.reset(new MemDefsUses(MFI));
+ const MachineFrameInfo *MFI = Fn->getFrameInfo();
+ IM.reset(new MemDefsUses(Fn->getDataLayout(), MFI));
}
- if (!searchRange(MBB, SuccBB->begin(), SuccBB->end(), RegDU, *IM, Filler,
- Slot))
+ if (!searchRange(MBB, SuccBB->begin(), SuccBB->end(), RegDU, *IM, Slot,
+ Filler))
return false;
insertDelayFiller(Filler, BrMap);
// Select the successor with the larget edge weight.
auto &Prob = getAnalysis<MachineBranchProbabilityInfo>();
- MachineBasicBlock *S = *std::max_element(B.succ_begin(), B.succ_end(),
- [&](const MachineBasicBlock *Dst0,
- const MachineBasicBlock *Dst1) {
- return Prob.getEdgeWeight(&B, Dst0) < Prob.getEdgeWeight(&B, Dst1);
- });
- return S->isLandingPad() ? nullptr : S;
+ MachineBasicBlock *S = *std::max_element(
+ B.succ_begin(), B.succ_end(),
+ [&](const MachineBasicBlock *Dst0, const MachineBasicBlock *Dst1) {
+ return Prob.getEdgeProbability(&B, Dst0) <
+ Prob.getEdgeProbability(&B, Dst1);
+ });
+ return S->isEHPad() ? nullptr : S;
}
std::pair<MipsInstrInfo::BranchType, MachineInstr *>
Filler::getBranch(MachineBasicBlock &MBB, const MachineBasicBlock &Dst) const {
- const MipsInstrInfo *TII = static_cast<const MipsInstrInfo *>(
- MBB.getParent()->getSubtarget().getInstrInfo());
+ const MipsInstrInfo *TII =
+ MBB.getParent()->getSubtarget<MipsSubtarget>().getInstrInfo();
MachineBasicBlock *TrueBB = nullptr, *FalseBB = nullptr;
SmallVector<MachineInstr*, 2> BranchInstrs;
SmallVector<MachineOperand, 2> Cond;
bool Filler::delayHasHazard(const MachineInstr &Candidate, RegDefsUses &RegDU,
InspectMemInstr &IM) const {
- bool HasHazard = (Candidate.isImplicitDef() || Candidate.isKill());
+ assert(!Candidate.isKill() &&
+ "KILL instructions should have been eliminated at this point.");
+
+ bool HasHazard = Candidate.isImplicitDef();
HasHazard |= IM.hasHazard(Candidate);
HasHazard |= RegDU.update(Candidate, 0, Candidate.getNumOperands());