/// \brief Perform target specific adjustments to the latency of a schedule
/// dependency.
void HexagonSubtarget::adjustSchedDependency(SUnit *Src, SUnit *Dst,
SDep &Dep) const {
MachineInstr *SrcInst = Src->getInstr();
MachineInstr *DstInst = Dst->getInstr();
if (!Src->isInstr() || !Dst->isInstr())
return;
const HexagonInstrInfo *QII = static_cast<const HexagonInstrInfo *>(getInstrInfo());
// Instructions with .new operands have zero latency.
if (QII->canExecuteInBundle(*SrcInst, *DstInst) &&
isBestZeroLatency(Src, Dst, QII)) {
Dep.setLatency(0);
return;
}
if (!hasV60TOps())
return;
// Don't adjust the latency of post-increment part of the instruction.
if (QII->isPostIncrement(*SrcInst) && Dep.isAssignedRegDep()) {
if (SrcInst->mayStore())
return;
if (Dep.getReg() != SrcInst->getOperand(0).getReg())
return;
} else if (QII->isPostIncrement(*DstInst) && Dep.getKind() == SDep::Anti) {
if (DstInst->mayStore())
return;
if (Dep.getReg() != DstInst->getOperand(0).getReg())
return;
} else if (QII->isPostIncrement(*DstInst) && DstInst->mayStore() &&
Dep.isAssignedRegDep()) {
MachineOperand &Op = DstInst->getOperand(DstInst->getNumOperands() - 1);
if (Op.isReg() && Dep.getReg() != Op.getReg())
return;
}
// Check if we need to change any the latency values when Phis are added.
if (useBSBScheduling() && SrcInst->isPHI()) {
changePhiLatency(*SrcInst, Dst, Dep);
return;
}
// If it's a REG_SEQUENCE, use its destination instruction to determine
// the correct latency.
if (DstInst->isRegSequence() && Dst->NumSuccs == 1)
DstInst = Dst->Succs[0].getSUnit()->getInstr();
// Try to schedule uses near definitions to generate .cur.
if (EnableDotCurSched && QII->isToBeScheduledASAP(*SrcInst, *DstInst) &&
isBestZeroLatency(Src, Dst, QII)) {
Dep.setLatency(0);
return;
}
updateLatency(*SrcInst, *DstInst, Dep);
}
