[opaque pointer type] Explicitly store the pointee type of the result of a GEP

Alternatively, this type could be derived on-demand whenever
getResultElementType is called - if someone thinks that's the better
choice (simple time/space tradeoff), I'm happy to give it a go.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238716 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/Instructions.h b/include/llvm/IR/Instructions.h
index 9f5e244f002123077122aa47ef1dd110b68fdf9d..8d8c530d2c6bab0e1c1b8909e47460cf0aaba592 100644 (file)
--- a/include/llvm/IR/Instructions.h
+++ b/include/llvm/IR/Instructions.h
@@ -810,6 +810,7 @@ inline Type *checkGEPType(Type *Ty) {
 ///
 class GetElementPtrInst : public Instruction {
   Type *SourceElementType;
+  Type *ResultElementType;
 
   GetElementPtrInst(const GetElementPtrInst &GEPI);
   void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr);
@@ -903,9 +904,12 @@ public:
   Type *getSourceElementType() const { return SourceElementType; }
 
   void setSourceElementType(Type *Ty) { SourceElementType = Ty; }
+  void setResultElementType(Type *Ty) { ResultElementType = Ty; }
 
   Type *getResultElementType() const {
-    return cast<PointerType>(getType()->getScalarType())->getElementType();
+    assert(ResultElementType ==
+           cast<PointerType>(getType()->getScalarType())->getElementType());
+    return ResultElementType;
   }
 
   /// \brief Returns the address space of this instruction's pointer type.
@@ -1028,7 +1032,10 @@ GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
     : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr,
                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
                   Values, InsertBefore),
-      SourceElementType(PointeeType) {
+      SourceElementType(PointeeType),
+      ResultElementType(getIndexedType(PointeeType, IdxList)) {
+  assert(ResultElementType ==
+         cast<PointerType>(getType()->getScalarType())->getElementType());
   init(Ptr, IdxList, NameStr);
 }
 GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
@@ -1038,7 +1045,10 @@ GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr,
     : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr,
                   OperandTraits<GetElementPtrInst>::op_end(this) - Values,
                   Values, InsertAtEnd),
-      SourceElementType(PointeeType) {
+      SourceElementType(PointeeType),
+      ResultElementType(getIndexedType(PointeeType, IdxList)) {
+  assert(ResultElementType ==
+         cast<PointerType>(getType()->getScalarType())->getElementType());
   init(Ptr, IdxList, NameStr);
 }
 

diff --git a/lib/IR/Instructions.cpp b/lib/IR/Instructions.cpp
index 332df4804dae73c8d2b145e4665299f410e1c671..1478bffe7c35664c61233e72759778e6ae2c7066 100644 (file)
--- a/lib/IR/Instructions.cpp
+++ b/lib/IR/Instructions.cpp
@@ -1249,7 +1249,8 @@ GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
                   OperandTraits<GetElementPtrInst>::op_end(this) -
                       GEPI.getNumOperands(),
                   GEPI.getNumOperands()),
-      SourceElementType(GEPI.SourceElementType) {
+      SourceElementType(GEPI.SourceElementType),
+      ResultElementType(GEPI.ResultElementType) {
   std::copy(GEPI.op_begin(), GEPI.op_end(), op_begin());
   SubclassOptionalData = GEPI.SubclassOptionalData;
 }

diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index cac80accc32f4d511598ec244708d3abea44b816..8c72641da9e7a7fbb3ce15ce7fe466009868e00a 100644 (file)
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -400,8 +400,11 @@ 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))
+  if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
     GEP->setSourceElementType(
         TypeMapper->remapType(GEP->getSourceElementType()));
+    GEP->setResultElementType(
+        TypeMapper->remapType(GEP->getResultElementType()));
+  }
   I->mutateType(TypeMapper->remapType(I->getType()));
 }