+ // Loop through the frame references and allocate for them as necessary.
+ for (int ref = 0, e = FrameReferenceInsns.size(); ref < e ; ++ref) {
+ MachineBasicBlock::iterator I =
+ FrameReferenceInsns[ref].getMachineInstr();
+ MachineInstr *MI = I;
+ for (unsigned idx = 0, e = MI->getNumOperands(); idx != e; ++idx) {
+ // Consider replacing all frame index operands that reference
+ // an object allocated in the local block.
+ if (MI->getOperand(idx).isFI()) {
+ int FrameIdx = MI->getOperand(idx).getIndex();
+
+ assert(MFI->isObjectPreAllocated(FrameIdx) &&
+ "Only pre-allocated locals expected!");
+
+ DEBUG(dbgs() << "Considering: " << *MI);
+ if (TRI->needsFrameBaseReg(MI, LocalOffsets[FrameIdx])) {
+ unsigned BaseReg = 0;
+ int64_t Offset = 0;
+ int64_t FrameSizeAdjust =
+ StackGrowsDown ? MFI->getLocalFrameSize() : 0;
+
+ DEBUG(dbgs() << " Replacing FI in: " << *MI);
+
+ // If we have a suitable base register available, use it; otherwise
+ // create a new one. Note that any offset encoded in the
+ // instruction itself will be taken into account by the target,
+ // so we don't have to adjust for it here when reusing a base
+ // register.
+ std::pair<unsigned, int64_t> RegOffset;
+ if (lookupCandidateBaseReg(BaseRegisters, RegOffset,
+ FrameSizeAdjust,
+ LocalOffsets[FrameIdx],
+ MI, TRI)) {
+ DEBUG(dbgs() << " Reusing base register " <<
+ RegOffset.first << "\n");
+ // We found a register to reuse.
+ BaseReg = RegOffset.first;
+ Offset = FrameSizeAdjust + LocalOffsets[FrameIdx] -
+ RegOffset.second;
+ } else {
+ // No previously defined register was in range, so create a
+ // new one.
+ int64_t InstrOffset = TRI->getFrameIndexInstrOffset(MI, idx);
+ const MachineFunction *MF = MI->getParent()->getParent();
+ const TargetRegisterClass *RC = TRI->getPointerRegClass(*MF);
+ BaseReg = Fn.getRegInfo().createVirtualRegister(RC);
+
+ DEBUG(dbgs() << " Materializing base register " << BaseReg <<
+ " at frame local offset " <<
+ LocalOffsets[FrameIdx] + InstrOffset << "\n");
+
+ // Tell the target to insert the instruction to initialize
+ // the base register.
+ // MachineBasicBlock::iterator InsertionPt = Entry->begin();
+ TRI->materializeFrameBaseRegister(Entry, BaseReg, FrameIdx,
+ InstrOffset);
+
+ // The base register already includes any offset specified
+ // by the instruction, so account for that so it doesn't get
+ // applied twice.
+ Offset = -InstrOffset;
+
+ int64_t BaseOffset = FrameSizeAdjust + LocalOffsets[FrameIdx] +
+ InstrOffset;
+ BaseRegisters.push_back(
+ std::pair<unsigned, int64_t>(BaseReg, BaseOffset));