[opaque pointer type] Track explicit GEP pointee type through in-memory IR

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236510 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/Instructions.h

@@ -801,6 +801,8 @@ inline Type *checkGEPType(Type *Ty) {
 /// access elements of arrays and structs
 ///
 class GetElementPtrInst : public Instruction {
+  Type *SourceElementType;
+
   GetElementPtrInst(const GetElementPtrInst &GEPI);
   void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr);
 
@@ -823,6 +825,13 @@ public:
                                    const Twine &NameStr = "",
                                    Instruction *InsertBefore = nullptr) {
     unsigned Values = 1 + unsigned(IdxList.size());
+    if (!PointeeType)
+      PointeeType =
+          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
+    else
+      assert(
+          PointeeType ==
+          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType());
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertBefore);
   }
@@ -831,6 +840,13 @@ public:
                                    const Twine &NameStr,
                                    BasicBlock *InsertAtEnd) {
     unsigned Values = 1 + unsigned(IdxList.size());
+    if (!PointeeType)
+      PointeeType =
+          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
+    else
+      assert(
+          PointeeType ==
+          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType());
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertAtEnd);
   }
@@ -876,10 +892,9 @@ public:
     return cast<SequentialType>(Instruction::getType());
   }
 
-  Type *getSourceElementType() const {
+  Type *getSourceElementType() const { return SourceElementType; }
-    return cast<SequentialType>(getPointerOperandType()->getScalarType())
+
-        ->getElementType();
+  void setSourceElementType(Type *Ty) { SourceElementType = Ty; }
-  }
 
   Type *getResultElementType() const {
     return cast<PointerType>(getType()->getScalarType())->getElementType();
@@ -1002,23 +1017,21 @@ GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
                                      ArrayRef<Value *> IdxList, unsigned Values,
                                      const Twine &NameStr,
                                      Instruction *InsertBefore)
-    : Instruction(PointeeType ? getGEPReturnType(PointeeType, Ptr, IdxList)
+    : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr,
-                              : getGEPReturnType(Ptr, IdxList),
-                  GetElementPtr,
                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
-                  Values, InsertBefore) {
+                  Values, InsertBefore),
+      SourceElementType(PointeeType) {
   init(Ptr, IdxList, NameStr);
-  assert(!PointeeType || PointeeType == getSourceElementType());
 }
 GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
                                      ArrayRef<Value *> IdxList, unsigned Values,
                                      const Twine &NameStr,
                                      BasicBlock *InsertAtEnd)
-    : Instruction(getGEPReturnType(Ptr, IdxList), GetElementPtr,
+    : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr,
                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
-                  Values, InsertAtEnd) {
+                  Values, InsertAtEnd),
+      SourceElementType(PointeeType) {
   init(Ptr, IdxList, NameStr);
-  assert(!PointeeType || PointeeType == getSourceElementType());
 }
 
 

lib/IR/Instructions.cpp

@@ -1243,10 +1243,11 @@ void GetElementPtrInst::init(Value *Ptr, ArrayRef<Value *> IdxList,
 }
 
 GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
-  : Instruction(GEPI.getType(), GetElementPtr,
+    : Instruction(GEPI.getType(), GetElementPtr,
-                OperandTraits<GetElementPtrInst>::op_end(this)
+                  OperandTraits<GetElementPtrInst>::op_end(this) -
-                - GEPI.getNumOperands(),
+                      GEPI.getNumOperands(),
-                GEPI.getNumOperands()) {
+                  GEPI.getNumOperands()),
+      SourceElementType(GEPI.SourceElementType) {
   std::copy(GEPI.op_begin(), GEPI.op_end(), op_begin());
   SubclassOptionalData = GEPI.SubclassOptionalData;
 }

lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -1602,6 +1602,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
             // is a leading zero) we can fold the cast into this GEP.
             if (StrippedPtrTy->getAddressSpace() == GEP.getAddressSpace()) {
               GEP.setOperand(0, StrippedPtr);
+              GEP.setSourceElementType(XATy);
               return &GEP;
             }
             // Cannot replace the base pointer directly because StrippedPtr's

lib/Transforms/Utils/ValueMapper.cpp

@@ -400,5 +400,8 @@ void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
   }
   if (auto *AI = dyn_cast<AllocaInst>(I))
     AI->setAllocatedType(TypeMapper->remapType(AI->getAllocatedType()));
+  if (auto *GEP = dyn_cast<GetElementPtrInst>(I))
+    GEP->setSourceElementType(
+        TypeMapper->remapType(GEP->getSourceElementType()));
   I->mutateType(TypeMapper->remapType(I->getType()));
 }