#include "llvm/IR/Operator.h" #include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/Type.h" #include "ConstantsContext.h" namespace llvm { Type *GEPOperator::getSourceElementType() const { if (auto *I = dyn_cast<GetElementPtrInst>(this)) return I->getSourceElementType(); return cast<GetElementPtrConstantExpr>(this)->getSourceElementType(); } Type *GEPOperator::getResultElementType() const { if (auto *I = dyn_cast<GetElementPtrInst>(this)) return I->getResultElementType(); return cast<GetElementPtrConstantExpr>(this)->getResultElementType(); } bool GEPOperator::accumulateConstantOffset(const DataLayout &DL, APInt &Offset) const { assert(Offset.getBitWidth() == DL.getPointerSizeInBits(getPointerAddressSpace()) && "The offset must have exactly as many bits as our pointer."); for (gep_type_iterator GTI = gep_type_begin(this), GTE = gep_type_end(this); GTI != GTE; ++GTI) { ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand()); if (!OpC) return false; if (OpC->isZero()) continue; // Handle a struct index, which adds its field offset to the pointer. if (StructType *STy = dyn_cast<StructType>(*GTI)) { unsigned ElementIdx = OpC->getZExtValue(); const StructLayout *SL = DL.getStructLayout(STy); Offset += APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx)); continue; } // For array or vector indices, scale the index by the size of the type. APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth()); Offset += Index * APInt(Offset.getBitWidth(), DL.getTypeAllocSize(GTI.getIndexedType())); } return true; } }