fix the memory problem

Author: Mikhail Gudim

llvm/include/llvm/CodeGen/ReachingDefAnalysis.h

@@ -142,7 +142,7 @@ class ReachingDefAnalysis : public MachineFunctionPass {
 
   MBBReachingDefsInfo MBBReachingDefs;
   using MBBFrameObjsReachingDefsInfo =
-      std::vector<std::vector<SmallVector<int>>>;
+      DenseMap<unsigned, DenseMap<int, SmallVector<int>>>;
   // MBBFrameObjsReachingDefs[i][j] is a list of instruction indices (relative
   // to begining of MBB) that define frame index (j +
   // MF->getFrameInfo().getObjectIndexBegin()) in MBB i. This is used in

llvm/lib/CodeGen/ReachingDefAnalysis.cpp

@@ -71,8 +71,6 @@ void ReachingDefAnalysis::enterBasicBlock(MachineBasicBlock *MBB) {
          "Unexpected basic block number.");
   MBBReachingDefs.startBasicBlock(MBBNumber, NumRegUnits);
 
-  MBBFrameObjsReachingDefs[MBBNumber].resize(NumStackObjects, {-1});
-
   // Reset instruction counter in each basic block.
   CurInstr = 0;
 
@@ -150,8 +148,16 @@ void ReachingDefAnalysis::processDefs(MachineInstr *MI) {
       assert(FrameIndex >= 0 && "Can't handle negative frame indicies yet!");
       if (!isFIDef(*MI, FrameIndex, TII))
         continue;
-      MBBFrameObjsReachingDefs[MBBNumber][FrameIndex - ObjectIndexBegin]
-          .push_back(CurInstr);
+      if (MBBFrameObjsReachingDefs.contains(MBBNumber)) {
+        auto Frame2InstrIdx = MBBFrameObjsReachingDefs[MBBNumber];
+        if (Frame2InstrIdx.count(FrameIndex - ObjectIndexBegin) > 0)
+          Frame2InstrIdx[FrameIndex - ObjectIndexBegin].push_back(CurInstr);
+        else
+          Frame2InstrIdx[FrameIndex - ObjectIndexBegin] = {CurInstr};
+      } else {
+        MBBFrameObjsReachingDefs[MBBNumber] = {
+            {FrameIndex - ObjectIndexBegin, {CurInstr}}};
+      }
     }
     if (!isValidRegDef(MO))
       continue;
@@ -307,7 +313,6 @@ void ReachingDefAnalysis::init() {
   NumStackObjects = MF->getFrameInfo().getNumObjects();
   ObjectIndexBegin = MF->getFrameInfo().getObjectIndexBegin();
   MBBReachingDefs.init(MF->getNumBlockIDs());
-  MBBFrameObjsReachingDefs.resize(MF->getNumBlockIDs());
   // Initialize the MBBOutRegsInfos
   MBBOutRegsInfos.resize(MF->getNumBlockIDs());
   LoopTraversal Traversal;
@@ -344,8 +349,8 @@ int ReachingDefAnalysis::getReachingDef(MachineInstr *MI, Register Reg) const {
 
   if (Register::isStackSlot(Reg)) {
     int FrameIndex = Register::stackSlot2Index(Reg);
-    for (int Def :
-         MBBFrameObjsReachingDefs[MBBNumber][FrameIndex - ObjectIndexBegin]) {
+    for (int Def : MBBFrameObjsReachingDefs.lookup(MBBNumber).lookup(
+             FrameIndex - ObjectIndexBegin)) {
       if (Def >= InstId)
         break;
       DefRes = Def;