AllocaInst* Variables::changeLocal(Value* value, PointerType* newType) {
AllocaInst *oldTarget = dyn_cast<AllocaInst>(value);
PointerType* oldPointerType = dyn_cast<PointerType>(oldTarget->getType());
PointerType *oldType = dyn_cast<PointerType>(oldPointerType->getElementType());
AllocaInst *newTarget = NULL;
errs() << "Changing the precision of pointer variable \"" << oldTarget->getName() << "\" from " << *oldType
<< " to " << *newType << ".\n";
if (diffTypes(newType, oldType)) {
newTarget = new AllocaInst(newType, getInt32(1), "", oldTarget);
// we are not calling getAlignment because in this case double requires 16. Investigate further.
unsigned alignment;
switch(newType->getElementType()->getTypeID()) {
case Type::FloatTyID:
alignment = 4;
break;
case Type::DoubleTyID:
alignment = 8;
break;
case Type::X86_FP80TyID:
alignment = 16;
break;
default:
alignment = 0;
}
newTarget->setAlignment(alignment); // depends on type? 8 for float? 16 for double?
newTarget->takeName(oldTarget);
// iterating through instructions using old AllocaInst
vector<Instruction*> erase;
Value::use_iterator it = oldTarget->use_begin();
#ifdef DEBUG
errs() << "\nOld target: ";
oldTarget->dump();
#endif
for(; it != oldTarget->use_end(); it++) {
#ifdef DEBUG
errs() << "\nA use: ";
it->dump();
errs() << "\n===============================\n";
errs() << "\nTransforming use\n";
#endif
bool is_erased = Transformer::transform(it, newTarget, oldTarget, newType, oldType, alignment);
if (!is_erased) {
erase.push_back(dyn_cast<Instruction>(*it));
}
#ifdef DEBUG
errs() << "\nDone transforming use\n";
#endif
}
// erasing uses of old instructions
for(unsigned int i = 0; i < erase.size(); i++) {
erase[i]->eraseFromParent();
}
// erase old instruction
//oldTarget->eraseFromParent();
#ifdef DEBUG
errs() << "DONE ALL TRANSFORMATION FOR POINTER\n";
#endif
} else {
errs() << "\tNo changes required.\n";
}
return newTarget;
}
