something wrong when I declare an int64 global variable in llvm - llvm

Question

I'm trying using llvm to build my own dsl.
Here I meet a strange problem when I'm using VS2017 win32 mode.
I defined a int64 global variable in one module with value 3 by external linkage.
Then when I declare this variable in another module and load it's value, I got 12884901891(same as 0x300000003). When I try this on Linux, it works well.
Hope someone can help me.
Blow is my code.CJITEngine is a simple singleton package.
PS. If I define the global variable with other type rather than int64, such as int32,float,double, this code can run well.
int main()
{
CJITEngine::Instance().Init();
DataLayout &layout = CJITEngine::Instance().GetDataLayout();
using fpType = void(*)(int64_t*);
fpType fp = nullptr;
string name("aaaaaaaa");
{
unique_ptr<Module> pModule = CJITEngine::Instance().CreateModule("module1");
IRBuilder<>& m_oBuilder = CJITEngine::Instance().GetIRBuilder();
Type* pType = m_oBuilder.getInt64Ty();
GlobalVariable* pVarValue = new GlobalVariable(*pModule, pType, false, GlobalValue::ExternalLinkage,
m_oBuilder.getInt64(3), name);
pVarValue->setAlignment(layout.getABITypeAlignment(pType));
pVarValue->setDSOLocal(true);
pModule->addModuleFlag(Module::Error, "NumRegisterParameters", m_oBuilder.getInt32(0));
pModule->addModuleFlag(Module::Error, "wchar_size", m_oBuilder.getInt32(2));
pModule->print(outs(), nullptr);
std::cout << "--------------------------------------------------------" << std::endl;
CJITEngine::Instance().AddModule(std::move(pModule));
}
/////////////////////////////////////////////////////////
{
unique_ptr<Module> pModule = CJITEngine::Instance().CreateModule("module2");
LLVMContext& m_oContext = CJITEngine::Instance().GetContext();
IRBuilder<>& m_oBuilder = CJITEngine::Instance().GetIRBuilder();
Type* pType = m_oBuilder.getInt64Ty();
GlobalVariable* pVarValue = new GlobalVariable(*pModule, pType, false, GlobalValue::ExternalLinkage,
nullptr, name);
pVarValue->setAlignment(layout.getABITypeAlignment(pType));
pVarValue->setDSOLocal(true);
FunctionType* pFuncType = FunctionType::get(m_oBuilder.getVoidTy(), {Type::getInt64PtrTy(m_oContext)}, false);
Function* pFunc = Function::Create(pFuncType, Function::ExternalLinkage, "func", pModule.get());
pFunc->setDSOLocal(true);
BasicBlock* pEntryBlock = BasicBlock::Create(m_oContext, "entry", pFunc);
BasicBlock* pExitBlock = BasicBlock::Create(m_oContext, "exit");
m_oBuilder.SetInsertPoint(pEntryBlock);
auto agr = pFunc->args().begin();
AllocaInst* pParam = m_oBuilder.CreateAlloca(agr->getType());
pParam->setAlignment(layout.getABITypeAlignment(Type::getInt64PtrTy(m_oContext)));
m_oBuilder.CreateAlignedStore(agr, pParam, layout.getABITypeAlignment(Type::getInt64PtrTy(m_oContext)));
Value* pStr = m_oBuilder.CreateAlignedLoad(pVarValue, layout.getABITypeAlignment(Type::getInt64Ty(m_oContext)));
Value* ppp= m_oBuilder.CreateAlignedLoad(pParam, layout.getABITypeAlignment(Type::getInt64PtrTy(m_oContext)));
m_oBuilder.CreateAlignedStore(pStr, ppp, layout.getABITypeAlignment(Type::getInt64Ty(m_oContext)));
m_oBuilder.CreateRetVoid();
pModule->addModuleFlag(Module::Error, "NumRegisterParameters", m_oBuilder.getInt32(0));
pModule->addModuleFlag(Module::Error, "wchar_size", m_oBuilder.getInt32(2));
pModule->print(outs(), nullptr);
CJITEngine::Instance().AddModule(std::move(pModule));
JITSymbol symbol = CJITEngine::Instance().FindSymbol("func");
fp = (fpType)static_cast<intptr_t>(cantFail(symbol.getAddress()));
int64_t x = 10;
fp(&x);
std::cout << hex << x << endl; // x is 0x300000003 here
}
return 0;
}