[CodeGen] Remove handling for lifetime.start/end on non-alloca

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -1425,10 +1425,9 @@ class SelectionDAG {
 
   /// Creates a LifetimeSDNode that starts (`IsStart==true`) or ends
   /// (`IsStart==false`) the lifetime of the portion of `FrameIndex` between
-  /// offsets `Offset` and `Offset + Size`.
+  /// offsets `0` and `Size`.
   LLVM_ABI SDValue getLifetimeNode(bool IsStart, const SDLoc &dl, SDValue Chain,
-                                   int FrameIndex, int64_t Size,
-                                   int64_t Offset = -1);
+                                   int FrameIndex, int64_t Size);
 
   /// Creates a PseudoProbeSDNode with function GUID `Guid` and
   /// the index of the block `Index` it is probing, as well as the attributes

llvm/include/llvm/CodeGen/SelectionDAGNodes.h

@@ -2004,25 +2004,17 @@ class FrameIndexSDNode : public SDNode {
 class LifetimeSDNode : public SDNode {
   friend class SelectionDAG;
   int64_t Size;
-  int64_t Offset; // -1 if offset is unknown.
 
   LifetimeSDNode(unsigned Opcode, unsigned Order, const DebugLoc &dl,
-                 SDVTList VTs, int64_t Size, int64_t Offset)
-      : SDNode(Opcode, Order, dl, VTs), Size(Size), Offset(Offset) {}
+                 SDVTList VTs, int64_t Size)
+      : SDNode(Opcode, Order, dl, VTs), Size(Size) {}
+
 public:
   int64_t getFrameIndex() const {
     return cast<FrameIndexSDNode>(getOperand(1))->getIndex();
   }
 
-  bool hasOffset() const { return Offset >= 0; }
-  int64_t getOffset() const {
-    assert(hasOffset() && "offset is unknown");
-    return Offset;
-  }
-  int64_t getSize() const {
-    assert(hasOffset() && "offset is unknown");
-    return Size;
-  }
+  int64_t getSize() const { return Size; }
 
   // Methods to support isa and dyn_cast
   static bool classof(const SDNode *N) {

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -2189,23 +2189,11 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
     unsigned Op = ID == Intrinsic::lifetime_start ? TargetOpcode::LIFETIME_START
                                                   : TargetOpcode::LIFETIME_END;
 
-    // Get the underlying objects for the location passed on the lifetime
-    // marker.
-    SmallVector<const Value *, 4> Allocas;
-    getUnderlyingObjects(CI.getArgOperand(1), Allocas);
-
-    // Iterate over each underlying object, creating lifetime markers for each
-    // static alloca. Quit if we find a non-static alloca.
-    for (const Value *V : Allocas) {
-      const AllocaInst *AI = dyn_cast<AllocaInst>(V);
-      if (!AI)
-        continue;
-
-      if (!AI->isStaticAlloca())
-        return true;
+    const AllocaInst *AI = cast<AllocaInst>(CI.getArgOperand(1));
+    if (!AI->isStaticAlloca())
+      return true;
 
-      MIRBuilder.buildInstr(Op).addFrameIndex(getOrCreateFrameIndex(*AI));
-    }
+    MIRBuilder.buildInstr(Op).addFrameIndex(getOrCreateFrameIndex(*AI));
     return true;
   }
   case Intrinsic::fake_use: {

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -22727,11 +22727,7 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
 
 SDValue DAGCombiner::visitLIFETIME_END(SDNode *N) {
   const auto *LifetimeEnd = cast<LifetimeSDNode>(N);
-  if (!LifetimeEnd->hasOffset())
-    return SDValue();
-
-  const BaseIndexOffset LifetimeEndBase(N->getOperand(1), SDValue(),
-                                        LifetimeEnd->getOffset(), false);
+  const BaseIndexOffset LifetimeEndBase(N->getOperand(1), SDValue(), 0, false);
 
   // We walk up the chains to find stores.
   SmallVector<SDValue, 8> Chains = {N->getOperand(0)};
@@ -29418,9 +29414,8 @@ bool DAGCombiner::mayAlias(SDNode *Op0, SDNode *Op1) const {
       return {false /*isVolatile*/,
               /*isAtomic*/ false,
               LN->getOperand(1),
-              (LN->hasOffset()) ? LN->getOffset() : 0,
-              (LN->hasOffset()) ? LocationSize::precise(LN->getSize())
-                                : LocationSize::beforeOrAfterPointer(),
+              0,
+              LocationSize::precise(LN->getSize()),
               (MachineMemOperand *)nullptr};
     // Default.
     return {false /*isvolatile*/,

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -786,10 +786,7 @@ static void AddNodeIDCustom(FoldingSetNodeID &ID, const SDNode *N) {
     break;
   case ISD::LIFETIME_START:
   case ISD::LIFETIME_END:
-    if (cast<LifetimeSDNode>(N)->hasOffset()) {
-      ID.AddInteger(cast<LifetimeSDNode>(N)->getSize());
-      ID.AddInteger(cast<LifetimeSDNode>(N)->getOffset());
-    }
+    ID.AddInteger(cast<LifetimeSDNode>(N)->getSize());
     break;
   case ISD::PSEUDO_PROBE:
     ID.AddInteger(cast<PseudoProbeSDNode>(N)->getGuid());
@@ -9364,7 +9361,7 @@ SDValue SelectionDAG::getMemIntrinsicNode(unsigned Opcode, const SDLoc &dl,
 
 SDValue SelectionDAG::getLifetimeNode(bool IsStart, const SDLoc &dl,
                                       SDValue Chain, int FrameIndex,
-                                      int64_t Size, int64_t Offset) {
+                                      int64_t Size) {
   const unsigned Opcode = IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END;
   const auto VTs = getVTList(MVT::Other);
   SDValue Ops[2] = {
@@ -9377,13 +9374,12 @@ SDValue SelectionDAG::getLifetimeNode(bool IsStart, const SDLoc &dl,
   AddNodeIDNode(ID, Opcode, VTs, Ops);
   ID.AddInteger(FrameIndex);
   ID.AddInteger(Size);
-  ID.AddInteger(Offset);
   void *IP = nullptr;
   if (SDNode *E = FindNodeOrInsertPos(ID, dl, IP))
     return SDValue(E, 0);
 
-  LifetimeSDNode *N = newSDNode<LifetimeSDNode>(
-      Opcode, dl.getIROrder(), dl.getDebugLoc(), VTs, Size, Offset);
+  LifetimeSDNode *N = newSDNode<LifetimeSDNode>(Opcode, dl.getIROrder(),
+                                                dl.getDebugLoc(), VTs, Size);
   createOperands(N, Ops);
   CSEMap.InsertNode(N, IP);
   InsertNode(N);

llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp

@@ -303,10 +303,7 @@ BaseIndexOffset BaseIndexOffset::match(const SDNode *N,
   if (const auto *LS0 = dyn_cast<LSBaseSDNode>(N))
     return matchLSNode(LS0, DAG);
   if (const auto *LN = dyn_cast<LifetimeSDNode>(N)) {
-    if (LN->hasOffset())
-      return BaseIndexOffset(LN->getOperand(1), SDValue(), LN->getOffset(),
-                             false);
-    return BaseIndexOffset(LN->getOperand(1), SDValue(), false);
+    return BaseIndexOffset(LN->getOperand(1), SDValue(), 0, false);
   }
   return BaseIndexOffset();
 }

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -7596,32 +7596,17 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
 
     const int64_t ObjectSize =
         cast<ConstantInt>(I.getArgOperand(0))->getSExtValue();
-    Value *const ObjectPtr = I.getArgOperand(1);
-    SmallVector<const Value *, 4> Allocas;
-    getUnderlyingObjects(ObjectPtr, Allocas);
+    const AllocaInst *LifetimeObject = cast<AllocaInst>(I.getArgOperand(1));
 
-    for (const Value *Alloca : Allocas) {
-      const AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(Alloca);
-
-      // Could not find an Alloca.
-      if (!LifetimeObject)
-        continue;
-
-      // First check that the Alloca is static, otherwise it won't have a
-      // valid frame index.
-      auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject);
-      if (SI == FuncInfo.StaticAllocaMap.end())
-        return;
+    // First check that the Alloca is static, otherwise it won't have a
+    // valid frame index.
+    auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject);
+    if (SI == FuncInfo.StaticAllocaMap.end())
+      return;
 
-      const int FrameIndex = SI->second;
-      int64_t Offset;
-      if (GetPointerBaseWithConstantOffset(
-              ObjectPtr, Offset, DAG.getDataLayout()) != LifetimeObject)
-        Offset = -1; // Cannot determine offset from alloca to lifetime object.
-      Res = DAG.getLifetimeNode(IsStart, sdl, getRoot(), FrameIndex, ObjectSize,
-                                Offset);
-      DAG.setRoot(Res);
-    }
+    const int FrameIndex = SI->second;
+    Res = DAG.getLifetimeNode(IsStart, sdl, getRoot(), FrameIndex, ObjectSize);
+    DAG.setRoot(Res);
     return;
   }
   case Intrinsic::pseudoprobe: {

llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp

@@ -947,8 +947,7 @@ void SDNode::print_details(raw_ostream &OS, const SelectionDAG *G) const {
        << ASC->getDestAddressSpace()
        << ']';
   } else if (const LifetimeSDNode *LN = dyn_cast<LifetimeSDNode>(this)) {
-    if (LN->hasOffset())
-      OS << "<" << LN->getOffset() << " to " << LN->getOffset() + LN->getSize() << ">";
+    OS << "<0 to " << LN->getSize() << ">";
   } else if (const auto *AA = dyn_cast<AssertAlignSDNode>(this)) {
     OS << '<' << AA->getAlign().value() << '>';
   }