// Replace Br with a branch which has the opposite condition code and a
// MachineBasicBlock operand MBBOpnd.
void MipsLongBranch::replaceBranch(MachineBasicBlock &MBB, Iter Br,
const DebugLoc &DL,
MachineBasicBlock *MBBOpnd) {
const MipsInstrInfo *TII = static_cast<const MipsInstrInfo *>(
MBB.getParent()->getSubtarget().getInstrInfo());
unsigned NewOpc = TII->getOppositeBranchOpc(Br->getOpcode());
const MCInstrDesc &NewDesc = TII->get(NewOpc);
MachineInstrBuilder MIB = BuildMI(MBB, Br, DL, NewDesc);
for (unsigned I = 0, E = Br->getDesc().getNumOperands(); I < E; ++I) {
MachineOperand &MO = Br->getOperand(I);
if (!MO.isReg()) {
assert(MO.isMBB() && "MBB operand expected.");
break;
}
MIB.addReg(MO.getReg());
}
MIB.addMBB(MBBOpnd);
if (Br->hasDelaySlot()) {
// Bundle the instruction in the delay slot to the newly created branch
// and erase the original branch.
assert(Br->isBundledWithSucc());
MachineBasicBlock::instr_iterator II = Br.getInstrIterator();
MIBundleBuilder(&*MIB).append((++II)->removeFromBundle());
}
Br->eraseFromParent();
}
