cast<BasicBlockSDNode>(N->getOperand(4))->getBasicBlock();
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
SDOperand CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC);
- unsigned Opc = getBCCForSetCC(CC);
// If this is a two way branch, then grab the fallthrough basic block
// argument and build a PowerPC branch pseudo-op, suitable for long branch
// conversion if necessary by the branch selection pass. Otherwise, emit a
// standard conditional branch.
if (N->getOpcode() == ISD::BRTWOWAY_CC) {
- MachineBasicBlock *Fallthrough =
- cast<BasicBlockSDNode>(N->getOperand(5))->getBasicBlock();
+ SDOperand CondTrueBlock = N->getOperand(4);
+ SDOperand CondFalseBlock = N->getOperand(5);
+
+ // If the false case is the current basic block, then this is a self loop.
+ // We do not want to emit "Loop: ... brcond Out; br Loop", as it adds an
+ // extra dispatch group to the loop. Instead, invert the condition and
+ // emit "Loop: ... br!cond Loop; br Out
+ if (cast<BasicBlockSDNode>(CondFalseBlock)->getBasicBlock() == BB) {
+ std::swap(CondTrueBlock, CondFalseBlock);
+ CC = getSetCCInverse(CC,
+ MVT::isInteger(N->getOperand(2).getValueType()));
+ }
+
+ unsigned Opc = getBCCForSetCC(CC);
SDOperand CB = CurDAG->getTargetNode(PPC::COND_BRANCH, MVT::Other,
CondCode, getI32Imm(Opc),
- N->getOperand(4), N->getOperand(5),
+ CondTrueBlock, CondFalseBlock,
Chain);
- CurDAG->SelectNodeTo(N, PPC::B, MVT::Other, N->getOperand(5), CB);
+ CurDAG->SelectNodeTo(N, PPC::B, MVT::Other, CondFalseBlock, CB);
} else {
// Iterate to the next basic block
ilist<MachineBasicBlock>::iterator It = BB;
// the PowerPC Branch Selection pass to crash.
if (It == BB->getParent()->end()) It = Dest;
CurDAG->SelectNodeTo(N, PPC::COND_BRANCH, MVT::Other, CondCode,
- getI32Imm(Opc), N->getOperand(4),
+ getI32Imm(getBCCForSetCC(CC)), N->getOperand(4),
CurDAG->getBasicBlock(It), Chain);
}
return SDOperand(N, 0);