+/// getUnderlyingObjectForInstr - If this machine instr has memory reference
+/// information and it can be tracked to a normal reference to a known
+/// object, return the Value for that object. Otherwise return null.
+static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI,
+ const MachineFrameInfo *MFI) {
+ if (!MI->hasOneMemOperand() ||
+ !(*MI->memoperands_begin())->getValue() ||
+ (*MI->memoperands_begin())->isVolatile())
+ return 0;
+
+ const Value *V = (*MI->memoperands_begin())->getValue();
+ if (!V)
+ return 0;
+
+ V = getUnderlyingObject(V);
+ if (const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V)) {
+ // For now, ignore PseudoSourceValues which may alias LLVM IR values
+ // because the code that uses this function has no way to cope with
+ // such aliases.
+ if (PSV->isAliased(MFI))
+ return 0;
+ return V;
+ }
+
+ if (isIdentifiedObject(V))
+ return V;
+
+ return 0;
+}
+
+void ScheduleDAGInstrs::StartBlock(MachineBasicBlock *BB) {
+ if (MachineLoop *ML = MLI.getLoopFor(BB))
+ if (BB == ML->getLoopLatch()) {
+ MachineBasicBlock *Header = ML->getHeader();
+ for (MachineBasicBlock::livein_iterator I = Header->livein_begin(),
+ E = Header->livein_end(); I != E; ++I)
+ LoopLiveInRegs.insert(*I);
+ LoopRegs.VisitLoop(ML);
+ }
+}
+
+void ScheduleDAGInstrs::BuildSchedGraph(AliasAnalysis *AA) {
+ // We'll be allocating one SUnit for each instruction, plus one for
+ // the region exit node.