//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: libcpp-has-no-threads, pre-sm-60
// UNSUPPORTED: windows && pre-sm-70
//  ... test crashes clang

// <cuda/std/atomic>

// template <class Integral>
//     Integral
//     atomic_fetch_sub(volatile atomic<Integral>* obj, Integral op);
//
// template <class Integral>
//     Integral
//     atomic_fetch_sub(atomic<Integral>* obj, Integral op);
//
// template <class T>
//     T*
//     atomic_fetch_sub(volatile atomic<T*>* obj, ptrdiff_t op);
//
// template <class T>
//     T*
//     atomic_fetch_sub(atomic<T*>* obj, ptrdiff_t op);

#include <cuda/std/atomic>
#include <cuda/std/type_traits>
#include <cuda/std/cassert>

#include "test_macros.h"
#include "atomic_helpers.h"
#include "cuda_space_selector.h"

template <class T, template<typename, typename> typename Selector, cuda::thread_scope>
struct TestFn {
  __host__ __device__
  void operator()() const {
    {
        typedef cuda::std::atomic<T> A;
        Selector<A, constructor_initializer> sel;
        A & t = *sel.construct();
        cuda::std::atomic_init(&t, T(3));
        assert(cuda::std::atomic_fetch_sub(&t, T(2)) == T(3));
        assert(t == T(1));
    }
    {
        typedef cuda::std::atomic<T> A;
        Selector<volatile A, constructor_initializer> sel;
        volatile A & t = *sel.construct();
        cuda::std::atomic_init(&t, T(3));
        assert(cuda::std::atomic_fetch_sub(&t, T(2)) == T(3));
        assert(t == T(1));
    }
  }
};

template <class T, template<typename, typename> typename Selector>
__host__ __device__
void testp()
{
    {
        typedef cuda::std::atomic<T> A;
        typedef typename cuda::std::remove_pointer<T>::type X;
        Selector<A, constructor_initializer> sel;
        A & t = *sel.construct();
        cuda::std::atomic_init(&t, T(3*sizeof(X)));
        assert(cuda::std::atomic_fetch_sub(&t, 2) == T(3*sizeof(X)));
        assert(t == T(1*sizeof(X)));
    }
    {
        typedef cuda::std::atomic<T> A;
        typedef typename cuda::std::remove_pointer<T>::type X;
        Selector<volatile A, constructor_initializer> sel;
        volatile A & t = *sel.construct();
        cuda::std::atomic_init(&t, T(3*sizeof(X)));
        assert(cuda::std::atomic_fetch_sub(&t, 2) == T(3*sizeof(X)));
        assert(t == T(1*sizeof(X)));
    }
}

int main(int, char**)
{
    NV_DISPATCH_TARGET(
    NV_IS_HOST,(
        TestEachIntegralType<TestFn, local_memory_selector>()();
        TestEachFloatingPointType<TestFn, local_memory_selector>()();
        testp<int*, local_memory_selector>();
        testp<const int*, local_memory_selector>();
    ),
    NV_PROVIDES_SM_70,(
        TestEachIntegralType<TestFn, local_memory_selector>()();
        TestEachFloatingPointType<TestFn, local_memory_selector>()();
        testp<int*, local_memory_selector>();
        testp<const int*, local_memory_selector>();
    ))

    NV_IF_TARGET(NV_IS_DEVICE,(
        TestEachIntegralType<TestFn, shared_memory_selector>()();
        TestEachFloatingPointType<TestFn, shared_memory_selector>()();
        testp<int*, shared_memory_selector>();
        testp<const int*, shared_memory_selector>();
        TestEachIntegralType<TestFn, global_memory_selector>()();
        TestEachFloatingPointType<TestFn, global_memory_selector>()();
        testp<int*, global_memory_selector>();
        testp<const int*, global_memory_selector>();
    ))

    return 0;
}
