Now that RegistersDefinedFromSameValue handles one instruction being an

[oota-llvm.git] / lib / CodeGen / LiveStackAnalysis.cpp

diff --git a/lib/CodeGen/LiveStackAnalysis.cpp b/lib/CodeGen/LiveStackAnalysis.cpp
index 92aec6a8e3a043c139eeb40d32ed030d4b8b37d6..939e795b4a382a4728b4c41f807cb820e3a9f6ea 100644 (file)
--- a/lib/CodeGen/LiveStackAnalysis.cpp
+++ b/lib/CodeGen/LiveStackAnalysis.cpp
@@ -28,6 +28,8 @@ char LiveStacks::ID = 0;
 INITIALIZE_PASS(LiveStacks, "livestacks",
                 "Live Stack Slot Analysis", false, false)
 
+char &llvm::LiveStacksID = LiveStacks::ID;
+
 void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addPreserved<SlotIndexes>();
@@ -42,12 +44,29 @@ void LiveStacks::releaseMemory() {
   S2RCMap.clear();
 }
 
-bool LiveStacks::runOnMachineFunction(MachineFunction &) {
+bool LiveStacks::runOnMachineFunction(MachineFunction &MF) {
+  TRI = MF.getTarget().getRegisterInfo();
   // FIXME: No analysis is being done right now. We are relying on the
   // register allocators to provide the information.
   return false;
 }
 
+LiveInterval &
+LiveStacks::getOrCreateInterval(int Slot, const TargetRegisterClass *RC) {
+  assert(Slot >= 0 && "Spill slot indice must be >= 0");
+  SS2IntervalMap::iterator I = S2IMap.find(Slot);
+  if (I == S2IMap.end()) {
+    I = S2IMap.insert(I, std::make_pair(Slot,
+            LiveInterval(TargetRegisterInfo::index2StackSlot(Slot), 0.0F)));
+    S2RCMap.insert(std::make_pair(Slot, RC));
+  } else {
+    // Use the largest common subclass register class.
+    const TargetRegisterClass *OldRC = S2RCMap[Slot];
+    S2RCMap[Slot] = TRI->getCommonSubClass(OldRC, RC);
+  }
+  return I->second;
+}
+
 /// print - Implement the dump method.
 void LiveStacks::print(raw_ostream &OS, const Module*) const {