+
+ // Don't allocate the new LocNo until it is needed.
+ unsigned NewLocNo = ~0u;
+
+ // Iterate over the overlaps between locInts and LI.
+ LocMapI.find(LI->beginIndex());
+ if (!LocMapI.valid())
+ continue;
+ LiveInterval::iterator LII = LI->advanceTo(LI->begin(), LocMapI.start());
+ LiveInterval::iterator LIE = LI->end();
+ while (LocMapI.valid() && LII != LIE) {
+ // At this point, we know that LocMapI.stop() > LII->start.
+ LII = LI->advanceTo(LII, LocMapI.start());
+ if (LII == LIE)
+ break;
+
+ // Now LII->end > LocMapI.start(). Do we have an overlap?
+ if (LocMapI.value() == OldLocNo && LII->start < LocMapI.stop()) {
+ // Overlapping correct location. Allocate NewLocNo now.
+ if (NewLocNo == ~0u) {
+ MachineOperand MO = MachineOperand::CreateReg(LI->reg, false);
+ MO.setSubReg(locations[OldLocNo].getSubReg());
+ NewLocNo = getLocationNo(MO);
+ DidChange = true;
+ }
+
+ SlotIndex LStart = LocMapI.start();
+ SlotIndex LStop = LocMapI.stop();
+
+ // Trim LocMapI down to the LII overlap.
+ if (LStart < LII->start)
+ LocMapI.setStartUnchecked(LII->start);
+ if (LStop > LII->end)
+ LocMapI.setStopUnchecked(LII->end);
+
+ // Change the value in the overlap. This may trigger coalescing.
+ LocMapI.setValue(NewLocNo);
+
+ // Re-insert any removed OldLocNo ranges.
+ if (LStart < LocMapI.start()) {
+ LocMapI.insert(LStart, LocMapI.start(), OldLocNo);
+ ++LocMapI;
+ assert(LocMapI.valid() && "Unexpected coalescing");
+ }
+ if (LStop > LocMapI.stop()) {
+ ++LocMapI;
+ LocMapI.insert(LII->end, LStop, OldLocNo);
+ --LocMapI;
+ }
+ }
+
+ // Advance to the next overlap.
+ if (LII->end < LocMapI.stop()) {
+ if (++LII == LIE)
+ break;
+ LocMapI.advanceTo(LII->start);
+ } else {
+ ++LocMapI;
+ if (!LocMapI.valid())
+ break;
+ LII = LI->advanceTo(LII, LocMapI.start());
+ }
+ }