-
-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;
-}