continue;
}
- if (UntieRegs && MO.isTied())
- MI->untieRegOperand(Idx);
-
if (!SpillSubRegs && MO.getSubReg())
return false;
// We cannot fold a load instruction into a def.
if (LoadMI && MO.isDef())
return false;
// Tied use operands should not be passed to foldMemoryOperand.
- if (!MI->isRegTiedToDefOperand(Idx))
+ if (UntieRegs || !MI->isRegTiedToDefOperand(Idx))
FoldOps.push_back(Idx);
}
MachineInstrSpan MIS(MI, MI->getParent());
+ SmallVector<std::pair<unsigned, unsigned> > TiedOps;
+ if (UntieRegs)
+ for (unsigned Idx : FoldOps) {
+ MachineOperand &MO = MI->getOperand(Idx);
+ if (!MO.isTied())
+ continue;
+ unsigned Tied = MI->findTiedOperandIdx(Idx);
+ if (MO.isUse())
+ TiedOps.emplace_back(Tied, Idx);
+ else {
+ assert(MO.isDef() && "Tied to not use and def?");
+ TiedOps.emplace_back(Idx, Tied);
+ }
+ MI->untieRegOperand(Idx);
+ }
+
MachineInstr *FoldMI =
LoadMI ? TII.foldMemoryOperand(*MI, FoldOps, *LoadMI, &LIS)
: TII.foldMemoryOperand(*MI, FoldOps, StackSlot, &LIS, &VRM);
- if (!FoldMI)
+ if (!FoldMI) {
+ // Re-tie operands.
+ for (auto Tied : TiedOps)
+ MI->tieOperands(Tied.first, Tied.second);
return false;
+ }
// Remove LIS for any dead defs in the original MI not in FoldMI.
for (MIBundleOperands MO(*MI); MO.isValid(); ++MO) {