// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCUDACXX___CUDA_CHRONO_H
#define _LIBCUDACXX___CUDA_CHRONO_H

#include <cuda/std/detail/__config>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include <nv/target>

_LIBCUDACXX_BEGIN_NAMESPACE_STD

namespace chrono
{

inline _LIBCUDACXX_INLINE_VISIBILITY system_clock::time_point system_clock::now() noexcept
{
  NV_DISPATCH_TARGET(
    NV_IS_DEVICE,
    (uint64_t __time; asm volatile("mov.u64 %0, %%globaltimer;"
                                   : "=l"(__time)::);
     return time_point(duration_cast<duration>(nanoseconds(__time)));),
    NV_IS_HOST,
    (return time_point(duration_cast<duration>(nanoseconds(
      ::std::chrono::duration_cast<::std::chrono::nanoseconds>(::std::chrono::system_clock::now().time_since_epoch())
        .count())));));
}

inline _LIBCUDACXX_INLINE_VISIBILITY time_t system_clock::to_time_t(const system_clock::time_point& __t) noexcept
{
  return time_t(duration_cast<seconds>(__t.time_since_epoch()).count());
}

inline _LIBCUDACXX_INLINE_VISIBILITY system_clock::time_point system_clock::from_time_t(time_t __t) noexcept
{
  return time_point(seconds(__t));
  ;
}
} // namespace chrono

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___CUDA_CHRONO_H