[opaque pointer types] [NFC] DataLayout::getIndexedOffset: take source element type instead of pointer type and rename to getIndexedOffsetInType.

[eddyb]

Rebased on top of D16302 (on top of trunk).

[eddyb]

Rebased to account for renames in D16282.

[mjacob]

The title of this revision seems to be wrong. I don't see any changes to the API of gep_type_iterator.

include/llvm/IR/DataLayout.h

446 ↗

(On Diff #45598)

I'd like to hear another comment on the name before you commit this.

lib/IR/DataLayout.cpp

730–732 ↗

(On Diff #45598)

I don't really like this. If this is required, we should consider changing the generic_gep_type_iterator API first.

[eddyb]

Rebased on top of rL258474.

[mjacob]

LGTM

lib/IR/DataLayout.cpp

750 ↗

(On Diff #45631)

You could inline this variable.

llvm/trunk/include/llvm/IR/DataLayout.h

public:
 
   /// \brief Returns the size of largest legal integer type size, or 0 if none
   /// are set.
   unsigned getLargestLegalIntTypeSize() const;
 
   /// \brief Returns the offset from the beginning of the type for the specified
   /// indices.
   ///
+  /// Note that this takes the element type, not the pointer type.
   /// This is used to implement getelementptr.
-  uint64_t getIndexedOffset(Type *Ty, ArrayRef<Value *> Indices) const;
+  uint64_t getIndexedOffsetInType(Type *ElemTy, ArrayRef<Value *> Indices) const;
 
   /// \brief Returns a StructLayout object, indicating the alignment of the
   /// struct, its size, and the offsets of its fields.
   ///
   /// Note that this information is lazily cached.
   const StructLayout *getStructLayout(StructType *Ty) const;
 
   /// \brief Returns the preferred alignment of the specified global.

llvm/trunk/lib/Analysis/ConstantFolding.cpp

if (!isa<ConstantInt>(Ops[i])) {
         }
       }
       return nullptr;
     }
 
   unsigned BitWidth = DL.getTypeSizeInBits(IntPtrTy);
   APInt Offset =
       APInt(BitWidth,
-            DL.getIndexedOffset(
-                Ptr->getType(),
+            DL.getIndexedOffsetInType(
+                SrcElemTy,
                 makeArrayRef((Value * const *)Ops.data() + 1, Ops.size() - 1)));
   Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
 
   // If this is a GEP of a GEP, fold it all into a single GEP.
   while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
     SmallVector<Value *, 4> NestedOps(GEP->op_begin() + 1, GEP->op_end());
 
     // Do not try the incorporate the sub-GEP if some index is not a number.
     bool AllConstantInt = true;
     for (unsigned i = 0, e = NestedOps.size(); i != e; ++i)
       if (!isa<ConstantInt>(NestedOps[i])) {
         AllConstantInt = false;
         break;
       }
     if (!AllConstantInt)
       break;
 
     Ptr = cast<Constant>(GEP->getOperand(0));
-    Offset += APInt(BitWidth, DL.getIndexedOffset(Ptr->getType(), NestedOps));
+    SrcElemTy = GEP->getSourceElementType();
+    Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps));
     Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
   }
 
   // If the base value for this address is a literal integer value, fold the
   // getelementptr to the resulting integer value casted to the pointer type.
   APInt BasePtr(BitWidth, 0);
   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
     if (CE->getOpcode() == Instruction::IntToPtr) {

llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

if (auto *Global = dyn_cast_or_null<GlobalVariable>(GV->getVariable())) {
     addLinkageName(*VariableDIE, GV->getLinkageName());
   } else if (const ConstantInt *CI =
                  dyn_cast_or_null<ConstantInt>(GV->getVariable())) {
     addConstantValue(*VariableDIE, CI, GTy);
   } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV->getVariable())) {
     addToAccelTable = true;
     // GV is a merged global.
     DIELoc *Loc = new (DIEValueAllocator) DIELoc;
-    Value *Ptr = CE->getOperand(0);
-    MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
+    auto *Ptr = cast<GlobalValue>(CE->getOperand(0));
+    MCSymbol *Sym = Asm->getSymbol(Ptr);
     DD->addArangeLabel(SymbolCU(this, Sym));
     addOpAddress(*Loc, Sym);
     addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
     SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
     addUInt(*Loc, dwarf::DW_FORM_udata,
-            Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
+            Asm->getDataLayout().getIndexedOffsetInType(Ptr->getValueType(), Idx));
     addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
     addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
   }
 
   if (addToAccelTable) {
     DD->addAccelName(GV->getName(), *VariableDIE);
 
     // If the linkage name is different than the name, go ahead and output

llvm/trunk/lib/IR/DataLayout.cpp

Type *DataLayout::getSmallestLegalIntType(LLVMContext &C, unsigned Width) const {
   return nullptr;
 }
 
 unsigned DataLayout::getLargestLegalIntTypeSize() const {
   auto Max = std::max_element(LegalIntWidths.begin(), LegalIntWidths.end());
   return Max != LegalIntWidths.end() ? *Max : 0;
 }
 
-uint64_t DataLayout::getIndexedOffset(Type *ptrTy,
+uint64_t DataLayout::getIndexedOffsetInType(Type *ElemTy,
                                             ArrayRef<Value *> Indices) const {
-  Type *Ty = ptrTy;
-  assert(Ty->isPointerTy() && "Illegal argument for getIndexedOffset()");
   uint64_t Result = 0;
 
   // We can use 0 as the address space as we don't need
   // to get pointer types back from gep_type_iterator.
   unsigned AS = 0;
   generic_gep_type_iterator<Value* const*>
-    TI = gep_type_begin(ptrTy->getPointerElementType(), AS, Indices);
-  for (unsigned CurIDX = 0, EndIDX = Indices.size(); CurIDX != EndIDX;
-       ++CurIDX, ++TI) {
-    if (StructType *STy = dyn_cast<StructType>(*TI)) {
-      assert(Indices[CurIDX]->getType() ==
-             Type::getInt32Ty(ptrTy->getContext()) &&
+    GTI = gep_type_begin(ElemTy, AS, Indices),
+    GTE = gep_type_end(ElemTy, AS, Indices);
+  for (; GTI != GTE; ++GTI) {
+    Value *Idx = GTI.getOperand();
+    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+      assert(Idx->getType() ==
+             Type::getInt32Ty(ElemTy->getContext()) &&
              "Illegal struct idx");
-      unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue();
+      unsigned FieldNo = cast<ConstantInt>(Idx)->getZExtValue();
 
       // Get structure layout information...
       const StructLayout *Layout = getStructLayout(STy);
 
       // Add in the offset, as calculated by the structure layout info...
       Result += Layout->getElementOffset(FieldNo);
-
-      // Update Ty to refer to current element
-      Ty = STy->getElementType(FieldNo);
     } else {
-      // Update Ty to refer to current element
-      Ty = cast<SequentialType>(Ty)->getElementType();
-
       // Get the array index and the size of each array element.
-      if (int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue())
-        Result += (uint64_t)arrayIdx * getTypeAllocSize(Ty);
+      if (int64_t arrayIdx = cast<ConstantInt>(Idx)->getSExtValue())
+        Result += (uint64_t)arrayIdx * getTypeAllocSize(GTI.getIndexedType());
     }
   }
 
   return Result;
 }
 
 /// getPreferredAlignment - Return the preferred alignment of the specified
 /// global.  This includes an explicitly requested alignment (if the global

llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp

if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UI)) {
         if (NonConstantIdx)
           return false;
         GEPNonConstantIdx = Indices.pop_back_val();
         if (!GEPNonConstantIdx->getType()->isIntegerTy(32))
           return false;
         HadDynamicAccess = true;
       } else
         GEPNonConstantIdx = NonConstantIdx;
-      uint64_t GEPOffset = DL.getIndexedOffset(GEP->getPointerOperandType(),
+      uint64_t GEPOffset = DL.getIndexedOffsetInType(GEP->getSourceElementType(),
                                                      Indices);
       // See if all uses can be converted.
       if (!CanConvertToScalar(GEP, Offset+GEPOffset, GEPNonConstantIdx))
         return false;
       IsNotTrivial = true;  // Can't be mem2reg'd.
       HadNonMemTransferAccess = true;
       continue;
     }
 
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
       SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end());
       Value* GEPNonConstantIdx = nullptr;
       if (!GEP->hasAllConstantIndices()) {
         assert(!NonConstantIdx &&
                "Dynamic GEP reading from dynamic GEP unsupported");
         GEPNonConstantIdx = Indices.pop_back_val();
       } else
         GEPNonConstantIdx = NonConstantIdx;
-      uint64_t GEPOffset = DL.getIndexedOffset(GEP->getPointerOperandType(),
+      uint64_t GEPOffset = DL.getIndexedOffsetInType(GEP->getSourceElementType(),
                                                      Indices);
       ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, GEPNonConstantIdx);
       GEP->eraseFromParent();
       continue;
     }
 
     IRBuilder<> Builder(User);
 
     if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
void SROA::isSafeGEP(GetElementPtrInst *GEPI,
   SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end());
   // If this GEP is non-constant then the last operand must have been a
   // dynamic index into a vector.  Pop this now as it has no impact on the
   // constant part of the offset.
   if (NonConstant)
     Indices.pop_back();
 
   const DataLayout &DL = GEPI->getModule()->getDataLayout();
-  Offset += DL.getIndexedOffset(GEPI->getPointerOperandType(), Indices);
+  Offset += DL.getIndexedOffsetInType(GEPI->getSourceElementType(), Indices);
   if (!TypeHasComponent(Info.AI->getAllocatedType(), Offset, NonConstantIdxSize,
                         DL))
     MarkUnsafe(Info, GEPI);
 }
 
 /// isHomogeneousAggregate - Check if type T is a struct or array containing
 /// elements of the same type (which is always true for arrays).  If so,
 /// return true with NumElts and EltTy set to the number of elements and the
void SROA::RewriteGEP(GetElementPtrInst *GEPI, AllocaInst *AI, uint64_t Offset,
   SmallVector<Value*, 8> Indices(GEPI->op_begin() + 1, GEPI->op_end());
   // If the GEP was dynamic then it must have been a dynamic vector lookup.
   // In this case, it must be the last GEP operand which is dynamic so keep that
   // aside until we've found the constant GEP offset then add it back in at the
   // end.
   Value* NonConstantIdx = nullptr;
   if (!GEPI->hasAllConstantIndices())
     NonConstantIdx = Indices.pop_back_val();
-  Offset += DL.getIndexedOffset(GEPI->getPointerOperandType(), Indices);
+  Offset += DL.getIndexedOffsetInType(GEPI->getSourceElementType(), Indices);
 
   RewriteForScalarRepl(GEPI, AI, Offset, NewElts);
 
   Type *T = AI->getAllocatedType();
   Type *IdxTy;
   uint64_t OldIdx = FindElementAndOffset(T, OldOffset, IdxTy, DL);
   if (GEPI->getOperand(0) == AI)
     OldIdx = ~0ULL; // Force the GEP to be rewritten.