+// MergeOpsUpdate - call MergeOps and update MemOps and merges accordingly on
+// success.
+void ARMLoadStoreOpt::MergeOpsUpdate(MachineBasicBlock &MBB,
+ MemOpQueue &memOps,
+ unsigned memOpsBegin, unsigned memOpsEnd,
+ unsigned insertAfter, int Offset,
+ unsigned Base, bool BaseKill,
+ int Opcode,
+ ARMCC::CondCodes Pred, unsigned PredReg,
+ unsigned Scratch,
+ DebugLoc dl,
+ SmallVector<MachineBasicBlock::iterator, 4> &Merges) {
+ // First calculate which of the registers should be killed by the merged
+ // instruction.
+ const unsigned insertPos = memOps[insertAfter].Position;
+
+ SmallSet<unsigned, 4> UnavailRegs;
+ SmallSet<unsigned, 4> KilledRegs;
+ DenseMap<unsigned, unsigned> Killer;
+ for (unsigned i = 0; i < memOpsBegin; ++i) {
+ if (memOps[i].Position < insertPos && memOps[i].isKill) {
+ unsigned Reg = memOps[i].Reg;
+ if (memOps[i].Merged)
+ UnavailRegs.insert(Reg);
+ else {
+ KilledRegs.insert(Reg);
+ Killer[Reg] = i;
+ }
+ }
+ }
+ for (unsigned i = memOpsEnd, e = memOps.size(); i != e; ++i) {
+ if (memOps[i].Position < insertPos && memOps[i].isKill) {
+ unsigned Reg = memOps[i].Reg;
+ KilledRegs.insert(Reg);
+ Killer[Reg] = i;
+ }
+ }
+
+ SmallVector<std::pair<unsigned, bool>, 8> Regs;
+ for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) {
+ unsigned Reg = memOps[i].Reg;
+ if (UnavailRegs.count(Reg))
+ // Register is killed before and it's not easy / possible to update the
+ // kill marker on already merged instructions. Abort.
+ return;
+
+ // If we are inserting the merged operation after an unmerged operation that
+ // uses the same register, make sure to transfer any kill flag.
+ bool isKill = memOps[i].isKill || KilledRegs.count(Reg);
+ Regs.push_back(std::make_pair(Reg, isKill));
+ }
+
+ // Try to do the merge.
+ MachineBasicBlock::iterator Loc = memOps[insertAfter].MBBI;
+ ++Loc;
+ if (!MergeOps(MBB, Loc, Offset, Base, BaseKill, Opcode,
+ Pred, PredReg, Scratch, dl, Regs))
+ return;
+
+ // Merge succeeded, update records.
+ Merges.push_back(prior(Loc));
+ for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) {
+ // Remove kill flags from any unmerged memops that come before insertPos.
+ if (Regs[i-memOpsBegin].second) {
+ unsigned Reg = Regs[i-memOpsBegin].first;
+ if (KilledRegs.count(Reg)) {
+ unsigned j = Killer[Reg];
+ memOps[j].MBBI->getOperand(0).setIsKill(false);
+ memOps[j].isKill = false;
+ }
+ }
+ MBB.erase(memOps[i].MBBI);
+ memOps[i].Merged = true;
+ }
+}
+