// Insert Defs and Uses of MI into the sets RegDefs and RegUses.
void Filler::insertDefsUses(MachineBasicBlock::instr_iterator MI,
SmallSet<unsigned, 32> &RegDefs,
SmallSet<unsigned, 32> &RegUses) {
// If MI is a call or return, just examine the explicit non-variadic operands.
MCInstrDesc MCID = MI->getDesc();
unsigned E = MI->isCall() || MI->isReturn() ? MCID.getNumOperands()
: MI->getNumOperands();
for (unsigned I = 0; I != E; ++I) {
const MachineOperand &MO = MI->getOperand(I);
unsigned Reg;
if (!MO.isReg() || !(Reg = MO.getReg()))
continue;
if (MO.isDef())
RegDefs.insert(Reg);
else if (MO.isUse())
RegUses.insert(Reg);
}
// Call & return instructions defines SP implicitly. Implicit defines are not
// included in the RegDefs set of calls but instructions modifying SP cannot
// be inserted in the delay slot of a call/return as these instructions are
// expanded to multiple instructions with SP modified before the branch that
// has the delay slot.
if (MI->isCall() || MI->isReturn())
RegDefs.insert(Lanai::SP);
}
// runOnMachineBasicBlock - Fill in delay slots for the given basic block.
// There is one or two delay slot per delayed instruction.
bool Filler::runOnMachineBasicBlock(MachineBasicBlock &MBB) {
bool Changed = false;
LastFiller = MBB.instr_end();
for (MachineBasicBlock::instr_iterator I = MBB.instr_begin();
I != MBB.instr_end(); ++I) {
if (I->getDesc().hasDelaySlot()) {
MachineBasicBlock::instr_iterator InstrWithSlot = I;
MachineBasicBlock::instr_iterator J = I;
// Treat RET specially as it is only instruction with 2 delay slots
// generated while all others generated have 1 delay slot.
if (I->getOpcode() == Lanai::RET) {
// RET is generated as part of epilogue generation and hence we know
// what the two instructions preceding it are and that it is safe to
// insert RET above them.
MachineBasicBlock::reverse_instr_iterator RI(I);
assert(RI->getOpcode() == Lanai::LDW_RI && RI->getOperand(0).isReg() &&
RI->getOperand(0).getReg() == Lanai::FP &&
RI->getOperand(1).isReg() &&
RI->getOperand(1).getReg() == Lanai::FP &&
RI->getOperand(2).isImm() && RI->getOperand(2).getImm() == -8);
++RI;
assert(RI->getOpcode() == Lanai::ADD_I_LO &&
RI->getOperand(0).isReg() &&
RI->getOperand(0).getReg() == Lanai::SP &&
RI->getOperand(1).isReg() &&
RI->getOperand(1).getReg() == Lanai::FP);
++RI;
MachineBasicBlock::instr_iterator FI(RI.base());
MBB.splice(std::next(I), &MBB, FI, I);
FilledSlots += 2;
} else {
if (!NopDelaySlotFiller && findDelayInstr(MBB, I, J)) {
MBB.splice(std::next(I), &MBB, J);
} else {
BuildMI(MBB, std::next(I), DebugLoc(), TII->get(Lanai::NOP));
}
++FilledSlots;
}
Changed = true;
// Record the filler instruction that filled the delay slot.
// The instruction after it will be visited in the next iteration.
LastFiller = ++I;
// Bundle the delay slot filler to InstrWithSlot so that the machine
// verifier doesn't expect this instruction to be a terminator.
MIBundleBuilder(MBB, InstrWithSlot, std::next(LastFiller));
}
}
return Changed;
}
void MipsCodeEmitter::emitInstruction(MachineBasicBlock::instr_iterator MI,
MachineBasicBlock &MBB) {
DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << *MI);
// Expand pseudo instruction. Skip if MI was not expanded.
if (((MI->getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo) &&
!expandPseudos(MI, MBB))
return;
MCE.processDebugLoc(MI->getDebugLoc(), true);
emitWord(getBinaryCodeForInstr(*MI));
++NumEmitted; // Keep track of the # of mi's emitted
MCE.processDebugLoc(MI->getDebugLoc(), false);
}
// Insert Defs and Uses of MI into the sets RegDefs and RegUses.
void Filler::insertDefsUses(MachineBasicBlock::instr_iterator MI,
SmallSet<unsigned, 32> &RegDefs,
SmallSet<unsigned, 32> &RegUses) {
// If MI is a call or return, just examine the explicit non-variadic operands.
MCInstrDesc MCID = MI->getDesc();
unsigned E = MI->isCall() || MI->isReturn() ? MCID.getNumOperands()
: MI->getNumOperands();
for (unsigned I = 0; I != E; ++I) {
const MachineOperand &MO = MI->getOperand(I);
unsigned Reg;
if (!MO.isReg() || !(Reg = MO.getReg()))
continue;
if (MO.isDef())
RegDefs.insert(Reg);
else if (MO.isUse())
RegUses.insert(Reg);
}
}